How to reproduce:
1. Create and open a new project
2. Open (Window -> Package Management -> Package Manager)
3. Press on the "+" icon at the top-left corner of the Package Manager
4. Press the "Add package by technical name" button
5. Enter "com.unity.ai.navigation" (for example) into the "Technical name" field
6. Enter a random version (4.9.78) into the "Version" field
7. Press the "Install" button
8. Observe the "Add package by technical name" panel

Expected result: Whichever field value is invalid is highlighted, but both values stay in the fields
Actual result: Both "Technical name" and "Version" values are emptied

Reproducible in: 6000.3.0a6, 6000.3.0b8, 6000.4.0a3
Not reproducible in: 2023.1.0a1, 6000.0.61f1, 6000.2.10f1, 6000.3.0a5

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