AssertionException thrown in SubScene.AddSceneEntities when code is reloaded with multiple SubScenes loaded

How to reproduce:
1. Open the “IN-149827” Project
2. In assets, open the "testscene" scene
3. Make sure the Entities and Entities Graphics module is installed in Package Manager
4. In assets, open DummyMono.cs
5. Add a comment to the script
6. Save the changes made to the script
7. Go back to the Editor and wait for the domain reload
8. Observe the changes in console

Actual result: “AssertionException” error in the console after domain reload
Expected result: No errors after domain reload

Reproducible with: 6000.5.7f1, 6000.7.0a2, 6000.7.0a3
Not reproducible with: 1.4.8 (6000.3.21f1), 6000.6.0b7, 6000.7.0a1
Fixed in: 6000.7.0a4

Reproducible on: MacOS 26.5 (M1), Windows 11 (By Reporter)
Not reproducible on: No other environments tested

Notes:

• The key to reproduce this issue is have two Subscenes
• The console Error:

AssertionException: Assertion failure. Value was False
Expected: True