1. Make a Prefab contains many children (Used for referencing)
2. Make an FSM that trying to manipulate those children
3. Add a couple of scripts to modify the scale/transform/Sprite renderer color
4. Cache some of the children's objects and drag some of them into the action's gameObject field directly.
5. Drag the prefab into the scene 5-6 times
6. Then modify the original prefab by adding some actions/deleting some
7. Try to do this couple of time
8. After a while, check the instantiated prefab (#5)
9. Somehow, It replaces those direct references to some cached variable and vice versa.
10. Removing the scene prefabs and replace them with the original prefab solves the problem
In the screenshot below, I just add new action inside the original prefab
then when I check the scene prefab
the variable changes from objParentBrick > ObjMonitor.
EDIT: I only test the GameObject variable. Make sure to go to PlayMode at least once to see the bug changes the variable