Hi Jean and thanks for your answer.
- how does GameObject are destroyed?
No idea yet. It's too random to pinpoint a cause at the moment.
- how can change be kept afterwards, play mode doesn't keep changes when you stop the playback right? If that's what you encounter, this is indeed a very bad bug.
That's why I submitted the bug to Unity a well
. This should not be possible in the first place but that's what is happening. It looks like a screw up in the editor but since I noticed gameobjects with FSM might be the only one affected, I also had to report the issue here.
- Are these gameobject prefab instances?
I don't think they are but I'll keep you updated if I notice such a pattern.
- Do you run several scenes in your hierarchy?
I do.
I hope this helps.
I havent' heard anything from Unity yet. If you need to contact them about it, the bug report number is 989698.
Thanks again.