Extremely frustrating, I keep having problems with syncing my device, a Forerunner 230 with the Garmin Connect app on Android.
What is even more frustrating is that there is nothing to help beyond the obvious instructions to turn on bluetooth
on both devices.
I rebooted, re-paired, many times, sometimes syncing suddenly worked then it stopped working again. Now I removed the device from
the device list and tried to re-pair, but that hangs forever. When showing the detail in the phone app, it shows "Authenticated", "Connected",
"Checked devices registration" and "Requesting device identification file failed".
For me, what I have here is essentially trash and unusable. I start to really regret buying a Garmin device because I had a lot of problems with it, and now the syncing and pairing problems on top of those.