As the title suggests, a property change can trigger multiple calls of PostEditChangeProperty. The function might run once or 3+ times. When creating a Blueprint subclass it also happened that with every Blueprint compile the number of calls incremented. I stopped at ~10 for 1 property change.
Steps to reproduce: New C++ project. New C++ Actor (or anyhting that has PostEditChangeProperty I guess). Override PostEditChangeProperty and just do a UE_LOG. If it behaves fine just try another class or project (I first noticed it when adjusting the character in the C++ FPS template).
edit: Forgot to mention to create a BP subclass and change the propperty in the editor. I assume this function is only called when making changes to the property in the editor as it is often enclosed in a WITH_EDITOR macro. Not sure on this one though.
I am not too confident when it comes to UE4 programming, therefore I am cautious when calling something a bug, but this issue seems so basic that I just don’t see what could be wrong on my end. I am still on 4.17.1 but the changelog of 4.17.2 didn’t mention anything relevant.