I have a 220 and it stopped syncing with the garmin connect phone on my app this week. I deleted and re-downloaded the app then said to forget the 220 so I could reconnect to see if that would solve anything. Now when I press connect on my phone, it correctly finds the 4 digit code displayed on my watch but when I press connect after about 10 seconds it says connection failed.
Any googling is pretty useless since garmin just says to redownload the app or to "make sure your watch bluetooth is on" like I never thought of that.