diff --git a/api/src/org/labkey/filters/ContentSecurityPolicyFilter.java b/api/src/org/labkey/filters/ContentSecurityPolicyFilter.java
index d55438013ea..ae58e441059 100644
--- a/api/src/org/labkey/filters/ContentSecurityPolicyFilter.java
+++ b/api/src/org/labkey/filters/ContentSecurityPolicyFilter.java
@@ -92,10 +92,10 @@ public String getHeaderName()
     static
     {
         // ReactJS hot reload uses localhost port 3001. If in dev mode, allow the browser to access that port for fonts
-        // and connections.
+        // and connections. Also allow webpack: protocol for source map loading by some external packages.
         if (AppProps.getInstance().isDevMode())
         {
-            registerAllowedSources("reactjs.hot.reload", Directive.Connection, "localhost:3001 ws://localhost:3001");
+            registerAllowedSources("reactjs.hot.reload", Directive.Connection, "localhost:3001 ws://localhost:3001 webpack:");
             registerAllowedSources("reactjs.hot.reload", Directive.Font, "localhost:3001");
         }
     }
diff --git a/assay/src/org/labkey/assay/plate/AssayPlateMetadataServiceImpl.java b/assay/src/org/labkey/assay/plate/AssayPlateMetadataServiceImpl.java
index ea2c98c3414..b4d7635f972 100644
--- a/assay/src/org/labkey/assay/plate/AssayPlateMetadataServiceImpl.java
+++ b/assay/src/org/labkey/assay/plate/AssayPlateMetadataServiceImpl.java
@@ -96,7 +96,6 @@
 import org.labkey.api.util.logging.LogHelper;
 import org.labkey.api.view.ActionURL;
 import org.labkey.assay.TSVProtocolSchema;
-import org.labkey.assay.plate.data.WellData;
 import org.labkey.assay.plate.model.WellBean;
 import org.labkey.assay.plate.query.PlateSchema;
 import org.labkey.assay.plate.query.PlateTable;
@@ -706,13 +705,13 @@ public PlateGridInfo(PlateUtils.GridInfo info, PlateSet plateSet, Set<String> me
 
         private @Nullable String getPrefixedValue(String annotation, String prefix)
         {
-            if (annotation != null && annotation.trim().toLowerCase().startsWith(prefix))
+            if (annotation != null)
             {
-                String[] parts = annotation.split(":");
-                if (parts.length > 1)
+                // Issue 52782: measure name may contain a colon
+                String[] parts = annotation.split(":", 2);
+                if (parts.length == 2 && parts[0].trim().equalsIgnoreCase(prefix))
                 {
-                    // Issue 52782: measure name may contain a colon, so we need to join the rest of the parts
-                    return StringUtils.join(parts, ":", 1, parts.length).trim();
+                    return parts[1].trim();
                 }
             }
             return null;