Same here - suggested solution not working properly for 4.19.
I’ve done some counting and what I’ve found is that the OtherBodyIndex returned by the overlap event does not account for all bones, but rather only bones that have a PhysicsBody attached to them,
while the GetBoneName goes over the entire hierarchy and does not skip bones that do not have a PhysicsBody.
It just seems both functions count the index in a different way,
knowing this it is at least possible to guess up manually determine up front what OtherBodyIndex translates into which BoneName - this of course is a very (very!) temporary workaround and should be fixed.