maybe a small possibility exists if your Actor variable is declared outside of a Function or Event scope. And it wouldn't be because of the Actor, but whenever and however the magic effects are handled for deletion.

I would be surprised if it didn't internally handle magic effects differently because they're lifetime is very short and they pile up in combat. at worst the magic effect becomes temporarily persistent and won't delete until you restart the game or move to a new cell (or whatever other criteria is met first).