@gadg3t42 this is an issue that some people have experienced in more recent updates. Rather than going on big story of possible reasons, I’ll just jump to the solution.
On your device, go to brave://sync-internals
Once there, you’ll find a button that says Disable Sync (Clear Data)
Click that and it will remove your device from the sync and set it back at the beginning. From there you can add it to the sync again if you have the sync code or you can just start a new sync chain.