This evening the clock on my FR630 was about 1 hour and 10 minutes slow. It's been fine for thre past couple of weeks and the only thing changed was upgrading to firmware 3.30 earlier today ... coincidence?
I tried rebooting watch and phone and re-pairing bluetooth but that didn't resolve the issue.
I have set it to manual for now which is ok but I like it set to automatic to ensure accurate time, all the time!
I have sent an email to Garmin and wondered if anyone else had seen this issue?