About once or twice a year - I lilke to back up and then rename my library so I have a backup and can go forward (and know when I last backed up at a glance). But this plays havoc with the ability to use the sync function. – I also had a corruption and rescued my library, but wanted to give it a new name to keep it clear which was the new library. That also messed up my ability to sync (I haven’t bothered to sort that out). I find the sync capability too complicated to use effectively, - so I don’t. Too many ways for it to not work, too complicated (and time consuming if it a big library) to even start over.
Not sure what I want you to do about it though!