How to reproduce:
1. Open the “AnimatorSetActive.zip“ project
2. Open the “UnityBug-AnimatorSetActive“ Scene
3. Enter Play Mode
4. Uncheck the “Child Active State“ Checkbox in the Game view
5. Observe the children GameObjects of the “Animator“ GameObject in the Hierarchy

Expected results: Both children GameObjects are disabled
Actual results: Only the “Child Not Referenced In Animation - Can Be Disabled“ child GameObject is disabled

Reproducible in: 2022.3.57f1, 6000.0.37f1, 6000.1.0b5, 6000.2.0a2

Reproduced on: Windows 11 Pro (23H2)
Not reproduced on: No other environment tested

Workaround: Disable the Animator Component first

Notes:
- If the Animator is disabled (by unchecking the “Animator State“ checkbox in the Game view) then both children GameObjects can be disabled
- The relevance of the issue is that a user has no control over setting the GameObject activity in the Editor if its “IsActive“ property is referenced in an Animation Clip (which is not necessarily playing)