I don’t have a Mac but I do run into the same issue with my Steam Deck while it’s docked. I have a Xbox controller and a controller from Logitech.
While the game is running, are you able to open up Steam’s controller settings? You might need to enable developer mode.
In the controller settings are you able to see something in the upper center-right about changing controller order?
In there just simply mess around with the controller order, might have to try various combos of controller order. That usually helps get the game to see the controller.