Composition tab goes missing when adding a property

[kjac]

Which Umbraco version are you using? (Please write the exact version, example: 10.1.0)

V15+

Bug summary

When adding a property to a group that is inherited via composition, the container tab disappears entirely from the UI. See screencast below.

Specifics

No response

Steps to reproduce

1. Create a composition type with a tab and a group.
2. Create a document type with a tab and a group of its own.
3. Add the composition type as composition for the document type.
4. Add a new property to the composition group on the document type.
5. The composition tab disappears along with all properties on it (including the newly added).

Screencast:

composition-tab-goes-missing.webm

Expected result / actual result

No response