Thanks for verifying. APEX is compatible with most devices that don't require special drivers or software but there are devices out there it may not be compatible with. If you have a spare mouse and keyboard around it would be worth testing them with your APEX.
We should also check if the controller is authenticating, this is needed for your mouse and keyboard to work. To do this, please disconnect and reconnect XIM to the console while watching XIM's startup light sequence. Do you see 4 green lights during this sequence? For reference the startup light sequence should look similar to this:
red, green, blue
red
green, green, green, green
red
If you do not see 4 green lights at startup and you have spare cables please test other cables with the controller.