UXML file opens dirty when ToggleButtonGroup is selected before leaving UI Stage

Steps to reproduce:

1. Create and open a new project
2. Create a 'NewUXMLTemplate' and instantiate it in the Hierarchy
3. In Project Settings -> UI Toolkit, Enable in-scene UI Authoring
4. Open the UXML GameObject in UI Stage
5. Create a Toggle Button Group
6. Save the changes and select the Toggle Button Group
7. Exit the UI Stage and enter it again
8. Observe the 'NewUXMLTemplate' header in UI stage

Actual results: The file is dirty (has an asterisk next to the name)

Expected results: The file is clean

Reproducible with versions: 6000.6.0b10, 6000.7.0a1, 6000.7.0a5

Can’t test with versions: 6000.0.82f1, 6000.3.23f1, 6000.5.10f1, 6000.6.0a7 (No UI Stage)

Tested on (OS): Windows 11 Pro (25H2)

Notes:

• Not reproducible in UI Builder