Convert all those RPC server events back to normal non-replicated events.
Overlap → switch has authority (Authority) means the overlap will only work on the server. Which is what you want.
Add items to player won’t fire because it requires the client to call it. You’re already on the server.
CL Add Item is the same. Non-replicated!
for loop → completed destroy actor doesn’t require the branch. Replicated actors only need to be destroyed on the server.