I just tried it and it seems to be working just fine. Are you sure you're not just missing the incredibly short press of the button? Try putting this line after that last line of code you gave me:
If that shows a message then the code is working just fine.if(key_action_pressed = true) { show_message("button pressed"); }
Are you sure you're not mistaking gamepad_check_button_pressed() for gamepad_check_button()? Just like GM's mouse functions, the former will only return true only when the button is pressed down the first time (for a single frame). The latter will return true the whole time the button is held.
I tried this :
It didn't working my game, but it worked when i tested it in a new game file.











