How to reproduce:
1. Open the user-attached project
2. Open the “SampleScene” Scene
3. Select the Cube GameObject in the Scene
4. Change the “Edit Mode” in the “Broken Editor Component” Script Component using the dropdown to “Mode Two”
5. Change the “Edit Mode” to “Mode Three”
6. Undo changes (CMD + Z)
Expected result: “Edit Mode” changes to “Mode Two”
Actual result: “Edit Mode” changes to “Mode One”
Reproducible with: 2020.3.36f1, 2020.3.40f1
Not reproducible with: 2020.3.35f1, 2021.3.12f1, 2022.1.20f1, 2022.2.0b11, 2023.1.0a14
Reproduced on: macOS Monterey 12.6 (Intel)
Note: The issue appears to be caused by a fix made to a bug that only affected 2020.3. Changeset: 07942ee70ac90ba9ccc134dfe5afebb2f4e50f22