Do you enable the Input for a Player Controller? If yes, then you have the Problem, that if you use get Controller the index is 0. This is allways the Server.
For this i have my own flow that works with Server and Client.
I made it this way:
Overlapping actor->CastTo(your Player)->from that get Controller and->castTo(your Player Controller)->enable Input.
With this i only enable the Input for the owning pawn. I am not sure if this above is right. I am not on my Computer. If you want i can post a screenshot from my Project.