Even when it works for the room, it never seems to work at all throughout the property. For example at my last 3 stays, the parking garage would not accept mobile key, the gym would not accept it nor would the Concierge Lounge for breakfast. I've learned to just skip the mobile key and stop at the front desk and get a physical one. Nothing worse than getting stuck at the parking gate, can't get out with 5 other cars behind you while no one answers the damn call button.