from the overlapping event - get other actor (it’s your pawn/char), then cast to pawn and from it, you can check If pawn locally controlled.
trigger fires on all players because all they have a local copy of this trigger. and also they have replicated copy of each other. when this replicated copy of player overlaps this trigger, then this client receives the overlap message from his local copy of trigger (I’m overlapping with another player that you can see, he replicates on your machine with his replication movement component).