diff --git a/projects/igniteui-angular/src/lib/data-operations/merge-strategy.ts b/projects/igniteui-angular/src/lib/data-operations/merge-strategy.ts
index 9bf47444fec..0c604bb21b6 100644
--- a/projects/igniteui-angular/src/lib/data-operations/merge-strategy.ts
+++ b/projects/igniteui-angular/src/lib/data-operations/merge-strategy.ts
@@ -7,6 +7,7 @@ import { GridType } from '../grids/common/grid.interface';
 export interface IMergeByResult {
     rowSpan: number;
     root?: any;
+    childRecords?: any[];
 }
 
 /**
@@ -75,10 +76,11 @@ export class DefaultMergeStrategy implements IGridMergeStrategy {
                 continue;
             }
             const recToUpdateData = recData ?? { recordRef: grid.isGhostRecord(rec) ? rec.recordRef : rec, cellMergeMeta: new Map<string, IMergeByResult>(), ghostRecord: rec.ghostRecord };
-            recToUpdateData.cellMergeMeta.set(field, { rowSpan: 1 });
+            recToUpdateData.cellMergeMeta.set(field, { rowSpan: 1, childRecords: [] });
             if (prev && comparer.call(this, prev.recordRef, recToUpdateData.recordRef, field, isDate, isTime) && prev.ghostRecord === recToUpdateData.ghostRecord) {
                 const root = prev.cellMergeMeta.get(field)?.root ?? prev;
                 root.cellMergeMeta.get(field).rowSpan += 1;
+                root.cellMergeMeta.get(field).childRecords.push(recToUpdateData);
                 recToUpdateData.cellMergeMeta.get(field).root = root;
             }
             prev = recToUpdateData;
diff --git a/projects/igniteui-angular/src/lib/grids/grid/grid.component.html b/projects/igniteui-angular/src/lib/grids/grid/grid.component.html
index 9631c1bd71a..f7b47ea5aec 100644
--- a/projects/igniteui-angular/src/lib/grids/grid/grid.component.html
+++ b/projects/igniteui-angular/src/lib/grids/grid/grid.component.html
@@ -69,7 +69,8 @@
                 | gridRowPinning:id:true:pipeTrigger
                 | gridFiltering:filteringExpressionsTree:filterStrategy:advancedFilteringExpressionsTree:id:pipeTrigger:filteringPipeTrigger:true
                 | gridSort:sortingExpressions:groupingExpressions:sortStrategy:id:pipeTrigger:true
-                | gridCellMerge:columnsToMerge:cellMergeMode:mergeStrategy:activeRowIndexes:true:pipeTrigger; as pinnedData) {
+                | gridCellMerge:columnsToMerge:cellMergeMode:mergeStrategy:pipeTrigger
+                | gridUnmergeActive:columnsToMerge:activeRowIndexes:true:pipeTrigger; as pinnedData) {
                 @if (pinnedData.length > 0) {
                     <div #pinContainer
                         [ngClass]="{
@@ -96,7 +97,8 @@
         | gridDetails:hasDetails:expansionStates:pipeTrigger
         | gridAddRow:false:pipeTrigger
         | gridRowPinning:id:false:pipeTrigger
-        | gridCellMerge:columnsToMerge:cellMergeMode:mergeStrategy:activeRowIndexes:false:pipeTrigger"
+        | gridCellMerge:columnsToMerge:cellMergeMode:mergeStrategy:pipeTrigger
+        | gridUnmergeActive:columnsToMerge:activeRowIndexes:false:pipeTrigger"
             let-rowIndex="index" [igxForScrollOrientation]="'vertical'" [igxForScrollContainer]="verticalScroll"
             [igxForContainerSize]="calcHeight"
             [igxForItemSize]="hasColumnLayouts ? rowHeight * multiRowLayoutRowSize + 1 : renderedRowHeight"
diff --git a/projects/igniteui-angular/src/lib/grids/grid/grid.component.ts b/projects/igniteui-angular/src/lib/grids/grid/grid.component.ts
index 247975c757f..307827b1922 100644
--- a/projects/igniteui-angular/src/lib/grids/grid/grid.component.ts
+++ b/projects/igniteui-angular/src/lib/grids/grid/grid.component.ts
@@ -34,7 +34,7 @@ import { IGridGroupingStrategy } from '../common/strategy';
 import { IgxGridValidationService } from './grid-validation.service';
 import { IgxGridDetailsPipe } from './grid.details.pipe';
 import { IgxGridSummaryPipe } from './grid.summary.pipe';
-import { IgxGridGroupingPipe, IgxGridPagingPipe, IgxGridSortingPipe, IgxGridFilteringPipe, IgxGridCellMergePipe } from './grid.pipes';
+import { IgxGridGroupingPipe, IgxGridPagingPipe, IgxGridSortingPipe, IgxGridFilteringPipe, IgxGridCellMergePipe, IgxGridUnmergeActivePipe } from './grid.pipes';
 import { IgxSummaryDataPipe } from '../summaries/grid-root-summary.pipe';
 import { IgxGridTransactionPipe, IgxHasVisibleColumnsPipe, IgxGridRowPinningPipe, IgxGridAddRowPipe, IgxGridRowClassesPipe, IgxGridRowStylesPipe, IgxStringReplacePipe } from '../common/pipes';
 import { IgxGridColumnResizerComponent } from '../resizing/resizer.component';
@@ -154,6 +154,7 @@ export interface IGroupingDoneEventArgs extends IBaseEventArgs {
         IgxGridDetailsPipe,
         IgxStringReplacePipe,
         IgxGridCellMergePipe,
+        IgxGridUnmergeActivePipe,
         IgxScrollInertiaDirective
     ],
     schemas: [CUSTOM_ELEMENTS_SCHEMA]
diff --git a/projects/igniteui-angular/src/lib/grids/grid/grid.pipes.ts b/projects/igniteui-angular/src/lib/grids/grid/grid.pipes.ts
index dedd1a26cc3..b6c2091ff0b 100644
--- a/projects/igniteui-angular/src/lib/grids/grid/grid.pipes.ts
+++ b/projects/igniteui-angular/src/lib/grids/grid/grid.pipes.ts
@@ -86,14 +86,76 @@ export class IgxGridCellMergePipe implements PipeTransform {
 
     constructor(@Inject(IGX_GRID_BASE) private grid: GridType) { }
 
-    public transform(collection: any, colsToMerge: ColumnType[], mergeMode: GridCellMergeMode, mergeStrategy: IGridMergeStrategy, activeRowIndexes: number[], pinned: boolean, _pipeTrigger: number) {
+    public transform(collection: any, colsToMerge: ColumnType[], mergeMode: GridCellMergeMode, mergeStrategy: IGridMergeStrategy, _pipeTrigger: number) {
+        if (colsToMerge.length === 0) {
+            return collection;
+        }
+        const result = DataUtil.merge(collection, colsToMerge, mergeStrategy, [], this.grid);
+        return result;
+    }
+}
+
+@Pipe({
+    name: 'gridUnmergeActive',
+    standalone: true
+})
+export class IgxGridUnmergeActivePipe implements PipeTransform {
+
+    constructor(@Inject(IGX_GRID_BASE) private grid: GridType) { }
+
+    public transform(collection: any, colsToMerge: ColumnType[], activeRowIndexes: number[], pinned: boolean, _pipeTrigger: number) {
         if (colsToMerge.length === 0) {
             return collection;
         }
         if (this.grid.hasPinnedRecords && !pinned && this.grid.pinning.rows !== RowPinningPosition.Bottom) {
             activeRowIndexes = activeRowIndexes.map(x => x - this.grid.pinnedRecordsCount);
         }
-        const result = DataUtil.merge(cloneArray(collection), colsToMerge, mergeStrategy, activeRowIndexes, this.grid);
+        activeRowIndexes = Array.from(new Set(activeRowIndexes)).filter(x => !isNaN(x));
+        const rootsToUpdate = [];
+        activeRowIndexes.forEach(index => {
+            const target = collection[index];
+            if (target) {
+                colsToMerge.forEach(col => {
+                    const colMeta = target.cellMergeMeta.get(col.field);
+                    const root = colMeta.root ||  (colMeta.rowSpan > 1 ? target : null);
+                    if (root) {
+                        rootsToUpdate.push(root);
+                    }
+                });
+            }
+        });
+        const uniqueRoots =  Array.from(new Set(rootsToUpdate));
+        if (uniqueRoots.length === 0) {
+            // if nothing to update, return
+            return collection;
+        }
+        let result = cloneArray(collection) as any;
+        uniqueRoots.forEach(x => {
+            const index = result.indexOf(x);
+            const colKeys = [...x.cellMergeMeta.keys()];
+            const cols = colsToMerge.filter(col => colKeys.indexOf(col.field) !== -1);
+            let res = [];
+            for (const col of cols) {
+
+                let childData = x.cellMergeMeta.get(col.field).childRecords;
+                const childRecs = childData.map(rec => rec.recordRef);
+                const isDate = col?.dataType === 'date' || col?.dataType === 'dateTime';
+                const isTime = col?.dataType === 'time' || col?.dataType === 'dateTime';
+                res = this.grid.mergeStrategy.merge(
+                    [x.recordRef, ...childRecs],
+                    col.field,
+                    col.mergingComparer,
+                    res,
+                    activeRowIndexes.map(ri => ri - index),
+                    isDate,
+                    isTime,
+                    this.grid);
+
+            }
+            result = result.slice(0, index).concat(res, result.slice(index + res.length));
+        });
+
+
         return result;
     }
 }
diff --git a/projects/igniteui-angular/src/lib/grids/hierarchical-grid/hierarchical-grid.component.html b/projects/igniteui-angular/src/lib/grids/hierarchical-grid/hierarchical-grid.component.html
index 276e89cb377..2b640e97ddd 100644
--- a/projects/igniteui-angular/src/lib/grids/hierarchical-grid/hierarchical-grid.component.html
+++ b/projects/igniteui-angular/src/lib/grids/hierarchical-grid/hierarchical-grid.component.html
@@ -51,7 +51,8 @@
                 | gridRowPinning:id:true:pipeTrigger
                 | gridFiltering:filteringExpressionsTree:filterStrategy:advancedFilteringExpressionsTree:id:pipeTrigger:filteringPipeTrigger:true
                 | gridSort:sortingExpressions:[]:sortStrategy:id:pipeTrigger:true
-                | gridCellMerge:columnsToMerge:cellMergeMode:mergeStrategy:activeRowIndexes:true:pipeTrigger; as pinnedData
+                | gridCellMerge:columnsToMerge:cellMergeMode:mergeStrategy:pipeTrigger
+                | gridUnmergeActive:columnsToMerge:activeRowIndexes:true:pipeTrigger; as pinnedData
             ) {
                 @if (pinnedData.length > 0) {
                     <div #pinContainer class="igx-grid__tr--pinned"
@@ -76,7 +77,8 @@
         | gridHierarchical:expansionStates:id:primaryKey:childLayoutKeys:pipeTrigger
         | gridAddRow:false:pipeTrigger
         | gridRowPinning:id:false:pipeTrigger
-        | gridCellMerge:columnsToMerge:cellMergeMode:mergeStrategy:activeRowIndexes:false:pipeTrigger"
+        | gridCellMerge:columnsToMerge:cellMergeMode:mergeStrategy:pipeTrigger
+        | gridUnmergeActive:columnsToMerge:activeRowIndexes:false:pipeTrigger"
             [igxForScrollOrientation]="'vertical'" [igxForScrollContainer]="verticalScroll"
             [igxForContainerSize]="calcHeight" [igxForItemSize]="renderedRowHeight" [igxForTrackBy]="trackChanges"
             #verticalScrollContainer (chunkPreload)="dataLoading($event)" (dataChanging)="dataRebinding($event)" (dataChanged)="dataRebound($event)">
diff --git a/projects/igniteui-angular/src/lib/grids/hierarchical-grid/hierarchical-grid.component.ts b/projects/igniteui-angular/src/lib/grids/hierarchical-grid/hierarchical-grid.component.ts
index 80c7c7c1f96..789b46b4453 100644
--- a/projects/igniteui-angular/src/lib/grids/hierarchical-grid/hierarchical-grid.component.ts
+++ b/projects/igniteui-angular/src/lib/grids/hierarchical-grid/hierarchical-grid.component.ts
@@ -50,7 +50,7 @@ import { IgxGridValidationService } from '../grid/grid-validation.service';
 import { IgxGridHierarchicalPipe, IgxGridHierarchicalPagingPipe } from './hierarchical-grid.pipes';
 import { IgxSummaryDataPipe } from '../summaries/grid-root-summary.pipe';
 import { IgxGridTransactionPipe, IgxHasVisibleColumnsPipe, IgxGridRowPinningPipe, IgxGridAddRowPipe, IgxGridRowClassesPipe, IgxGridRowStylesPipe, IgxStringReplacePipe } from '../common/pipes';
-import { IgxGridSortingPipe, IgxGridFilteringPipe, IgxGridCellMergePipe } from '../grid/grid.pipes';
+import { IgxGridSortingPipe, IgxGridFilteringPipe, IgxGridCellMergePipe, IgxGridUnmergeActivePipe } from '../grid/grid.pipes';
 import { IgxGridColumnResizerComponent } from '../resizing/resizer.component';
 import { IgxRowEditTabStopDirective } from '../grid.rowEdit.directive';
 import { IgxIconComponent } from '../../icon/icon.component';
@@ -353,7 +353,8 @@ export class IgxChildGridRowComponent implements AfterViewInit, OnInit {
         IgxGridHierarchicalPagingPipe,
         IgxStringReplacePipe,
         IgxGridCellMergePipe,
-        IgxScrollInertiaDirective
+        IgxScrollInertiaDirective,
+        IgxGridUnmergeActivePipe
     ],
     schemas: [CUSTOM_ELEMENTS_SCHEMA]
 })
diff --git a/projects/igniteui-angular/src/lib/grids/tree-grid/tree-grid.component.html b/projects/igniteui-angular/src/lib/grids/tree-grid/tree-grid.component.html
index 33c79416332..7195fcbf71b 100644
--- a/projects/igniteui-angular/src/lib/grids/tree-grid/tree-grid.component.html
+++ b/projects/igniteui-angular/src/lib/grids/tree-grid/tree-grid.component.html
@@ -53,7 +53,8 @@
                 | gridRowPinning:id:true:pipeTrigger
                 | treeGridFiltering:filteringExpressionsTree:filterStrategy:advancedFilteringExpressionsTree:pipeTrigger:filteringPipeTrigger:true
                 | treeGridSorting:sortingExpressions:treeGroupArea?.expressions:sortStrategy:pipeTrigger:true
-                | gridCellMerge:columnsToMerge:cellMergeMode:mergeStrategy:activeRowIndexes:true:pipeTrigger; as pinnedData
+                | gridCellMerge:columnsToMerge:cellMergeMode:mergeStrategy:pipeTrigger
+                | gridUnmergeActive:columnsToMerge:activeRowIndexes:true:pipeTrigger; as pinnedData
             ) {
                 @if (pinnedData.length > 0) {
                     <div #pinContainer
@@ -82,7 +83,8 @@
         | treeGridSummary:hasSummarizedColumns:summaryCalculationMode:summaryPosition:showSummaryOnCollapse:pipeTrigger:summaryPipeTrigger
         | treeGridAddRow:false:pipeTrigger
         | gridRowPinning:id:false:pipeTrigger
-        | gridCellMerge:columnsToMerge:cellMergeMode:mergeStrategy:activeRowIndexes:false:pipeTrigger"
+        | gridCellMerge:columnsToMerge:cellMergeMode:mergeStrategy:pipeTrigger
+        | gridUnmergeActive:columnsToMerge:activeRowIndexes:false:pipeTrigger"
             let-rowIndex="index" [igxForScrollOrientation]="'vertical'" [igxForScrollContainer]='verticalScroll'
             [igxForContainerSize]='calcHeight' [igxForItemSize]="renderedRowHeight" #verticalScrollContainer
             (dataChanging)="dataRebinding($event)" (dataChanged)="dataRebound($event)">
diff --git a/projects/igniteui-angular/src/lib/grids/tree-grid/tree-grid.component.ts b/projects/igniteui-angular/src/lib/grids/tree-grid/tree-grid.component.ts
index 4820bca8339..40196a62d0b 100644
--- a/projects/igniteui-angular/src/lib/grids/tree-grid/tree-grid.component.ts
+++ b/projects/igniteui-angular/src/lib/grids/tree-grid/tree-grid.component.ts
@@ -82,7 +82,7 @@ import { IgxGridDragSelectDirective } from '../selection/drag-select.directive';
 import { IgxGridBodyDirective } from '../grid.common';
 import { IgxGridHeaderRowComponent } from '../headers/grid-header-row.component';
 import { IgxTextHighlightService } from '../../directives/text-highlight/text-highlight.service';
-import { IgxGridCellMergePipe } from '../grid/grid.pipes';
+import { IgxGridCellMergePipe, IgxGridUnmergeActivePipe } from '../grid/grid.pipes';
 import { DefaultTreeGridMergeStrategy, IGridMergeStrategy } from '../../data-operations/merge-strategy';
 import { IgxScrollInertiaDirective } from '../../directives/scroll-inertia/scroll_inertia.directive';
 
@@ -173,7 +173,8 @@ let NEXT_ID = 0;
         IgxTreeGridAddRowPipe,
         IgxStringReplacePipe,
         IgxGridCellMergePipe,
-        IgxScrollInertiaDirective
+        IgxScrollInertiaDirective,
+        IgxGridUnmergeActivePipe
     ],
     schemas: [CUSTOM_ELEMENTS_SCHEMA]
 })
diff --git a/src/app/grid-cellMerging/grid-cellMerging.component.html b/src/app/grid-cellMerging/grid-cellMerging.component.html
index 73233eb9c1c..b578fb8c3ef 100644
--- a/src/app/grid-cellMerging/grid-cellMerging.component.html
+++ b/src/app/grid-cellMerging/grid-cellMerging.component.html
@@ -50,7 +50,7 @@ <h4 class="sample-title">Grid with cell merge</h4>
             Value: {{val}},Index: {{cell.row.index}}
           </ng-template>
     </igx-column>
-    <igx-column field="ShipCountry" header="Ship Country" width="200px" [merge]="true" sortable="true">
+    <igx-column field="ShipCountry" header="Ship Country" [merge]="true" width="200px" sortable="true">
     </igx-column>
     <igx-column field="OrderDate" header="Order Date" width="200px" [merge]="true" [groupable]="true" [dataType]="'date'" sortable="true">
     </igx-column>
@@ -70,8 +70,7 @@ <h4 class="sample-title">Grid with cell merge</h4>
     </igx-column>
     <igx-column field="Quantity" header="Quantity" width="150px" dataType="number">
     </igx-column>
-    <igx-paginator [perPage]="20">
-    </igx-paginator>
+
     <igx-action-strip>
         <igx-grid-pinning-actions></igx-grid-pinning-actions>
     </igx-action-strip>
diff --git a/src/app/grid-cellMerging/grid-cellMerging.component.ts b/src/app/grid-cellMerging/grid-cellMerging.component.ts
index 3374c5e606f..19c7ed681e1 100644
--- a/src/app/grid-cellMerging/grid-cellMerging.component.ts
+++ b/src/app/grid-cellMerging/grid-cellMerging.component.ts
@@ -38,7 +38,7 @@ import { INVOICE_DATA } from '../shared/invoiceData';
         FormsModule,
         IgxColumnComponent,
         IgxGridComponent,
-        IgxPaginatorComponent,
+        // IgxPaginatorComponent,
         IgxActionStripComponent,
         IgxGridPinningActionsComponent,
         IgxGridToolbarComponent,
@@ -66,6 +66,17 @@ export class GridCellMergingComponent {
     @ViewChild('grid1', { static: true }) public grid: IgxGridComponent;
     public data = INVOICE_DATA;
 
+    constructor(){
+        const allData = INVOICE_DATA
+        const length = INVOICE_DATA.length;
+        for (let i = 1; i <= 600_000; i++) {
+            const rnd = Math.floor(Math.random() * length);
+            allData.push(Object.assign({}, INVOICE_DATA[rnd]));
+        }
+
+        this.data = allData;
+    }
+
     public toggleStrategy() {
         if (this.treeGridMergeStrategy instanceof ByLevelTreeGridMergeStrategy) {
             this.treeGridMergeStrategy = new DefaultTreeGridMergeStrategy();