We found the cause for this regression: between 5.4 and 5.5 we fixed that weak object pointers get fixed up when actors are reinstanced (recreated after recompiling). This causes these bindings that previously automatically became stale and removed to stay alive and pile up. Weak object pointer fixup was working in the past, broken for a bit, then fixed again. You can get the 5.4 behavior again with this CVar or running this console command:
UObject.UseSerializeToFindWeakReferencers 0As a local workaround you can run that. Weak object pointers to an actor won’t survive if an actor gets recompiled, so other editor-time issues may appear.
I’ll work towards cleaning up these bindings explicitly, so that we can have the best of both worlds.