How to reproduce:
1. Import the attached "Hand_Drawn_Vines_001" Asset into Unity
2. In the Project window, select the imported Asset
3. In the Inspector, go to Meshes -> Unit Conversion -> Custom
4. Try to set up a Scale Factor to a negative value
Expected results: The Scale Factor can't be set to a negative value
Actual results: The Scale Factor can be set to a negative number
Reproducible with: 2021.3.44f1, 2022.3.48f1, 6000.0.21f1
Reproducible on: Windows 11 Pro
Not reproducible on: No other environment tested