I was recently having this issue with my sons Switch OLED. The right joy con will work attached to the switch, but not wirelessly. It had not been taken apart I just figured he broke it somehow, he's rough on things. I got a Switch OLED for Christmas, so I decided to try putting the known good right joy con from my unit on his to see if it would work. It work perfectly. I then put the joy con from his unit that is giving trouble onto my unit. To my surprise it connected and started working perfectly both on the unit and wirelessly. I then put the now working controller on his unit and it started working on the unit and wirelessly. I have no clue why that fixed the issue, but it did, at least for now. Maybe this will help someone else down the road.