UXML preview shows only black background in the Inspector when any element has a Filter applied

Steps to reproduce:

1. Create a new project
2. Create a new UI Document and open it in UI Builder(Assets > Create > UI Toolkit > UI Document)
3. Add a Button to the Hierarchy (or any other well visible element)
4. Select it and in the Inspector, find the Filters foldout
5. Click "+" to add a new filter function and select "Contrast" (or any other except "Custom")
6. From the Project window, select the .uxml asset
7. Observe its preview in the Inspector

Actual results: No preview is shown, only a black background

Expected results: Button (or any element) is shown in the preview

Reproducible with versions: 6000.6.0b1, 6000.6.0b6, 6000.7.0a3

Not reproducible with versions: 6000.5.6f1, 6000.6.0a7

Tested on (OS): Ubuntu 24.04, macOS 26.5 

Notes:

• Reproduces with any Filter type applied to any element