Video Player preview is not shown when Inspector preview is converted to Floating Window

Steps to reproduce:

1. Open the attached "video" project
2. Open the "SampleScene"
3. Enter Play mode
4. From the Hierarchy, select the "Video Player" GameObject
5. In the inspector, click on the "Default UI Material" dropdown and switch it to "Video Player"
6. Click on the three dots and select "Convert to Floating Window"
7. Observe the opened window

Actual results: The floating window does not show the Video Player preview and appears to reset back to the "Default UI Material" preview

Expected results: The floating window should preserve and display the selected "Video Player" preview after conversion

Reproducible with versions: 6000.4.1f1, 6000.4.3f1, 6000.5.0b4, 6000.6.0a3

Not reproducible with versions: 6000.3.12f1, 6000.4.0f1 (107f2798865e)

Tested on (OS): macOS 26.4

Notes:

• Also due to [Internal link] the dropdown cant be changed when window is converted, so there is no way to observe the Video Player preview in the Floating Window. Both issues likely stem from the same regression though