We ended up getting this same crash, Unreal Engine Issues and Bug Tracker (UE\-209483), I found the caused and fixed it and sent a PR https://github.com/EpicGames/UnrealEngine/pull/13545\.
Just mismatched incrementing handles in the private ctor.
Nick! It’s been a while. Thanks for fixing our bugs! I’ll get this one in.
It’s in UE Main