Forerunner 255 does not sync music automatically when connected to power

I have noticed, that 255m don't does auto-sync before a battery is under 20%. If the 20% mark is reached, auto-sync starts.

Thanks - I usually don't let my battery drain that low so will give it a try.

Does anyone know if that 20% mark is changeable?  My use case is that I typically plug in my phone every other night or so when I go to bed so usually the battery is above 50% so wouldn't trigger at the 20% mark but I'd like it to.

I always charge my watch with over 20% left. Still my watch always synchronizes with Spotify.

Interesting update - I had been using the beta version of the garmin connect app on my phone (Android).  Wondering why auto music seemed to be working for others but not me I reverted back to the non-beta garmin connect app and for the first time my Forefunner 255 music auto sync'ed the music providers (amazon music and playrun).  Not sure why that matters, maybe a bug.  I'll experiement a little more and if I can figure out the exact cause report it to Garmin (and back here as well).

Were you able to solve the problem? For weeks, when my watch is plugged into power, it constantly gives the warning 'music synchronization failed'. I'm really bored now.

Not really, no.  After several factory resets, the best I got to is that if I install amazon music while outside when the phone has GPS sync then the first time after a power on it will automatically sync reliably.  After that it's hit or miss.  Definitely less than half the time.  When it fails, there is no message that it even tried.  On even more rare occasions it do get that 'music synchronization failed' error but not really sure why.  If I could return my watch I would and I'd go back to my Vivoactive 4 which worked flawlessly but I'm stuck at this point.

It would be nice if someone from Garmin would contact me to help debug the problem - I'm a former software engineer so pretty tolerant of work arounds and debugging stuff and would love to look at some (or have someone at Garmin look at) the internal logs to see why it's failing so we could resolve it.  Unfortunately that seems like wishful thinking.  I've gone from a huge Garmin advocate to being really disappointed and frustrated.

OK after several months of frustration (I had given up) I have finally pinpointed some of the problem.  This is reliably repeatable.  When the last music I listened to had "My Music" selected as the provider and I plug the device in, it automatically syncs every time.  When any other app (Amazon Music, Playrun) was the last music I listened to there is no auto sync.

So at least I know how to make it auto-sync some of the time.  This is not really acceptable since the process of selecting "My Music" before plugging in is more annoying than just manually syncing from the menu in one of the other apps.  But at least this is a little more insight into what's going on.