How to reproduce:
1. Open the “IN-104601_MixedValueBugs“ project
2. Select “ExampleA“ and “ExampleB” in the Project window
3. In the Inspector change the “Number” mixed value to “1”
4. Undo the action (Ctrl + Z)
5. Observe the “Number” value

Expected result: The field is updated and displays the mixed value as dash (—)
Actual result: The field is not updated and stays as “1”

Reproducible with: 2022.3.63f1, 6000.0.0b13, 6000.0.51f1, 6000.1.6f1, 6000.2.0b5
Not reproducible with: 2022.2.0a8
Could not test with: 2022.2.0a9, 6000.0.0b12 (Different issue is present where trying to modify the field automatically inputs “0” or when you input “1” it is greyed out and does not change the value preventing accurate reproduction)

Reproducible on: macOS 15.5 (M1 Max), Windows 11 (by user)
Not reproducible on: no other environments tested

Note: This issue does not reproduce if you change the number to a value different than the “ExampleB” asset number