Akai Fire Quick Chopping Shortcut

Is there a way to use the shortcut or use the Fire itself to quick chop? I use mac but not sure if it's an OS problem or I still don't know all the shortcuts on the Fire. I was using it to make a beat and needed to use the quick chop, so pressed (command+U) it did nothing. I selected it from the edit menu manually and it worked. Does the Fire cancel out any other keyboard &/or mouse functions or shortcuts? Does anyone have ideas on faster or better ways of using this function or others with FL studio & Akai Fire? Thank you, this is my first post but didn't see one when I skimmed through. thank you