Short answer is sync does not work on Brave rewards. It is something they are working on for the future but I don’t exist now. If you are ever changing devices there’s an unofficial way to handle it now which is in the link below. Otherwise when you connect to Gemini or Uphold with your devices they will all go to the same wallet. But that’s about it
Check out ‘ I'm getting a new device, how do I backup my BAT/information? OR I need to reinstall, how do I save my BAT/information? at