I have a really similar problem and I would like to know if you solved your issue or not.
My idea about your problem is that at the really beginning of a game, the character spawns with an AIController, and right after this AIController is replaced by yours (as far as I understood during debugging sessions).
As a result, it is possible that is short period of time was enough for UE4 to start your timer.
BUT, what you’re talking about the actor still being destroyed without Destroy event is my problem right now, and I don’t know why…