Reproduction steps:
1. Open the attached “IN-106329.zip” project
2. Open the “MyScene” Scene
3. From the Hierarchy, select the “GameObject”
4. In the Inspector, observe the ”MyClass (Script)” Component
5. Make the Inspector wider
6. Observe the green Label expanding while the orange one remains the same size
7. Shrink the Inspector so that it is less than 300px
8. Observe the Labels

Expected result: Both Labels start shrinking when the Width is less than 300px
Actual result: Only the green Label is shrinking and the orange remains the same size

Reproducible with: 2022.1.0a1, 2022.3.63f1, 6000.0.53f1, 6000.1.11f1, 6000.2.0b9, 6000.3.0a1

Reproducible on: Windows 11
Not reproducible on: no other environment tested

Notes:
- The core issue is that an element's flex-grow setting is incorrectly preventing it from shrinking. The 300px width is the critical point because each Label has a flex-basis of 150px (150px + 150px = 300px). The flex-shrink: 1 property on both labels means they should both shrink when the container becomes narrower than this. However, the flex-grow: 0 on the first label is incorrectly overriding this, making it a fixed size during shrinking
- The same incorrect behaviour can be reproduced using C# and a Custom Inspector, UXML and a Custom Inspector and the UI Builder. To test in the UI Builder - open the “MyUXML.asset” (Assets > Resources) and repeat the reproduction steps by narrowing the viewport