Hello, pathfinding obstacles are GLOBAL, that is, 1 object is defined as an obstacle for all pathefinding behaviors in the game (even if in different objects, such as player 1, player 2, and player 3).
in the image of the events you sent, you are defining the obstacle several times, one for each player, you should use an event, (start layout=player1, player2, player3 or player family define obstacle)
and the obstacle must be a family with all these tilemap inside)
PS: an extra, the physical behavior also uses gravity in a GLOBAL way, what you define for an object will affect everyone in the same way.