new Spotify and Sync Failures

I had the same issues. Also running 5.10 firmware.
Once the app was installed I had failure after failure upon failure to sync. I signed into my wifi over and over and over. Each time it would say that I was successfully connected to wifi. Then when trying to sync it would fail. No wifi connection.(?) I even tried several times to use the wifi widget to get connected instead of doing it through the Spotify app. Each time the connection was successful only to fail as soon as I tried to sync a playlist. This went on for two days and many attempts. Day 3...everything worked. (sigh...)

Thanks for posting this. After many attempts in the last two days, I just let the watch sit. Today, it works fine. There must be something on the backend that has to take place. Anyway, its working now.

Ok, so after almost giving up for the night - it just started to work... No clue why, something Spotifys end?!?

Just my experience here too... I have a FR 645M. Firmware v4.20.
Decided to reach out to Garmin support, they simply pointed me to https://support.garmin.com/en-US/?faq=NP5CwjAhVN36MoazFOSrxA
I did those steps 5 times now. Reset the watch, resync'd, redone the steps outlined, checked my network - it didn't work.

My wife also had the same issue. She applied the same settings, it didn't work. Now she didn't change any setting since, and the sync magically started working this morning (after 2 days).
The one thing we did notice was on 645M, i got a message that the "spotify content expired" or something like that, then when i went to "update downloads" it started to sync, finally!

Garmin will probably say it's a user issue, but this does seem like a bug in your firmware setup. After reading the forums here, i'm glad i'm not the only one with these issues.
It does seem that "Spotify expired content" is something to do with it though.

Thanks,
Darren.