Welcome to the community. Is the console communication method set to USB instead of bluetooth? This is required if the controller supports it.
Settings > Devices > Controllers > Communication Method

-
It would also help to know if your controller is authenticating with XIM and your console. Please disconnect and reconnect XIM to the console while watching XIM's startup light sequence. Do you see 4 green lights during this sequence? This indicates controller authentication and is needed for your mouse and keyboard to function. 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.