Search field visually shows the stale character when overwriting a single character on UI Toolkit text fields

Steps to reproduce:

1. Create and open a new URP project
2. Enable the "Use New Hierarchy" in Edit -> Preferences -> General
3. Focus on the search field in the Hierarchy
4. Type "a" and press Enter
5. Select the text and write "b"
6. Observe the search field

Actual results: "a" is still written

Expected results: "b" overwrites "a"

Reproducible with versions: 6000.6.0a6

Not reproducible with versions: 6000.0.76f1, 6000.3.17f1, 6000.4.10f1, 6000.5.0b11, 6000.6.0a5

Tested on (OS): Windows 11 Pro (25H2)

Notes:

• Doesn't reproduce on IMGUI text fields, but is reproducible on any UI Toolkit text field
• Only reproduces when overwriting one letter strings (works on numbers too)
• After validation, the string appears correct