[GM] How to use 2 joysticks?

[J-Crew]

I'm making my game so that it's joystick compatible. I have 2 joysticks and only one can be used at a time. could someone try to help me wit this. Gamemaker reads that the 2nd controller is there but it doesn't respond to any of the buttons or control stick. (I'm using a universal converter that converts gamecube controllers.) Thanks in advance.