xbox elite series 2 controller broken

[quiet ridge]

i have an xbox elite series 2 controller thats broken in a very odd way. if its plugged into my computer while its dead itll work fine untill the computer receives input from my keyboard. after which the only buttons that work are the sticks, triggers and xbox button. if i unplug it itll stay "on" untill it dies. if i plug it back in while its not dead it will not respond at all. while unplugged it isint connected to anything but still remains on. ive tried on 2 different computers with the same results and a different controller (same model) works fine with the same cable. also sometimes the x logo glows way more brightly than usual or turns blue but i dont know why. it happens randomly