This seems to be due to a change in AActor::Tick that adds this check before calling the blueprint ReceiveTick:
if (GetClass()->HasAnyClassFlags(CLASS_CompiledFromBlueprint) || !GetClass()->HasAnyClassFlags(CLASS_Native))
while UnrealJS sets some classes as native in ExportUnrealEngineClasses.

ReceiveTick works when adding the CLASS_CompiledFromBlueprint flag like so:
Class->ClassFlags |= (CLASS_Native | CLASS_CompiledFromBlueprint);
but setting the class to both CLASS_Native and CLASS_CompiledFromBlueprint seems contradictory, just by the names of the flags.

Perhaps someone with more knowledge on the flags could answer if adding that flag is ok and shouldn't create side-effects?