I can't unsync my controller from my console

okay so I borrowed a friends controller and it works! So my two controllers just aren't unsyncing from the previous wireless receiver and computer I used them on, does anyone know how I can unsync them?

I've started experiencing this issue before the June update. Bought a new controller to test and now both are unsyncing. Sometimes while watching TV, they stay in sync, but the moment I press a button they unsync. Unfortunately I live in a country where
the console hasn't been officialy launched yet (it will on September) so I can't send my console to repair. I'm just hoping that the next updates will solve this. Otherwise I'll have to use wires forever... that's so Next-Gen :/

Also, I forgot to mention that the controller became unsynced with the console, and will not reconnect.

Ive rebooted my xbox unsynced my controller tried a different headset. Nothing seems to work.

Thanks for the reply.

When switching between chat modes, it fixes the issue for a second or two, then back to lower.

Even tried unsyncing my headset from the controller/profile. No fix.