"Add to Assistant" button shows no icon and does not recover for the rest of the Editor session

Steps to reproduce:

1. Create a new project with 7000.0.0a1 using the 3D URP template, let it finish importing, then close it
2. In Unity Hub, click the three dots next to that project, select "Save project as custom template", and create the template
3. In Unity Hub, click "New Project", select that custom template, and create the project
4. Open the new project and confirm the Console fills with "UDSFilesystem failed to acquire a read handle" errors
5. Install the AI Assistant package via "Window > Package Manager" if it is not already installed
6. Open the Console window containing the "Add to Assistant" button
7. Observe the button

Actual results: The "Add to Assistant" button is drawn with its label but no icon.

Expected results: The button shows its icon.

Reproducible with versions: 2.19.0-pre.2(7000.0.0a1)

Not reproducible with versions: 

Can’t test with versions: 

Tested on (OS): MacBook Pro - Tahoe 26.6.2