Sorry if my previous reply was confusing but I want to know where you want to change the owner at runtime cause all I can see in the blueprints is that they are all called automatically like “Begin Play”, “On Post Login”.
Do you have an event where you need to interact to that actor where the change of owner takes place.
If you have that kind of event that is I would like to see
Testing in my project I was able to change owner of an actor in runtime with no problems. Using Play as Client with 2 players. I have an “Interact Event” where the claiming of ownership takes place