I have a Garmin Edge 810 and I used the Garmin Connect Mobile app on my Lumia 730 (Windows 10 Mobile) to upload my rides via Bluetooth without any issues for many months. I don't carry my phone with me on my rides, but when I would arrive home, I would simply open the GCM app, hit the sync button and my ride (.fit file) would be uploaded to my Garmin (and Strava) accounts without a hitch.
Three days ago, I reset my Garmin and since then I haven't been able to sync via Bluetooth at all any longer. I know that there were some issues with the Garmin servers last weekend, but as far as I know, that's over now. However, what happens is the following: my Edge 810 and my mobile phone are connected alright, the Edge shows in the GCM app and when I hit "Sync", it syncs (blue, then green stripe at the bottom), but even though it says "sync complete", the activity is NOT uploaded to my Garmin (and Strava) accounts and is not shown there at all. The activity is there on the Edge though, and I can also sync it via USB and Garmin Express on my laptop (if I sync it there, it shows up as an activity in my Garmin Connect, unlike via Bluetooth).
I have reset the Edge 810 several times (both Factory and the so-called Super Master Reset including formatting, it still runs the up-to-date 6.30 firmware) and have tried unpairing the phone and uninstalling/reinstalling GCM on the phone. I'm at my wit's end, because nothing has worked, I still get the same error, except that according to GCM it's not an error (i.e. it shows "sync completed", but it doesn't actually sync the data). Could anyone help?