Steps to reproduce:

1. Create a project with 6000.0.8f1;
2. In the "Hierarchy" window make a right mouse click and select UI;
3. Select "Text - TextmeshPro"
4. Click" Import TPM Essentials;
5. Go to the "Inspector" tab;
6. Scroll to the "Material" section, which should be below the "Extra Settings";
7. Click the material hierarchy popup button;
8. Change "Material" to "Material Variant";
9. In the "Material Variant" window click "X";
10. Observe the window behavior;
11. Or in the "Material Variant" window set "Parent" to "Anton SDF - Drop shadow";
12. And play with the "Children" dropdown.

Actual results: Two videos are added in the "Attachments" section.

Expected results: Window changes should be smooth, without the window/text distortions.

Reproducible with versions: 2023.3.0a2, 6000.0.8f1

Not reproducible with versions: 2022.3.26f1

Can’t test with versions: 6000.0.6f1

Tested on (OS): MacOS, Sonoma 14.5