Solved! Go to Solution.
Did you have the Fitbit to a previous Samsung phone? I did a quick google search and it looks like people were having the same issue with their S20's and S10's as well.
If you type fitbit versa 2 bluetooth issues on google, this comes up:
On your phone, go to Settings > Bluetooth and turn Bluetooth off and back on. If your Fitbit device doesn't sync, restart it. ... If your Fitbit device still doesn't sync, remove all other Fitbit devices from your account and from the list of connected Bluetooth devices on your phone and try to sync.