How to reproduce:
1. Open the "UIToolkitBugsBundle.zip" project
2. Open the "UIDocument.uxml" in UI Builder
3. Expand any one USS file
4. Select any selector under the expanded USS file through a touchscreen monitor
5. Observe the UI Builder

Expected result: The selector is selected
Actual result: The selector is not selected

Reproducible in: 6000.1.0b9, 6000.1.3f1, 6000.2.0b1
Not reproducible in: 2022.1.0a1, 2022.3.62f1, 6000.0.49f1, 6000.1.0b8

Reproduced on: Windows 11 Pro (24H2)
Not reproduced on: No other environment tested

Notes:
- USS files can be expanded and collapsed through touchscreen monitors
- Library elements can be selected, but USS selectors and Hierarchy elements cannot be selected