Garmin edge 840 not syncing

the only way I found to reliably sync is to at the end of the ride turn the 840 off, then turn it back on while keeping my phone close by, this will pretty much always sync the ride to my cellphone garmin connect, if it does not I repeat this with my watch off as well (happens rarely). If I leave it running it is rare it syncs on its own, I always have to power cycle it, never had this issue with my older 510 or with my watch which always sync no problem right away. Also if I go in garmin connect the 840 shows pretty much as always syncing, the arrow is always spinning regardless of what's going on.

Any more info on this, it was syncing slow, now it shows my Edge 840, as not connected, although bluetooth is connected on phone and device. Beyond frustrated. What is going on GARMIN! 

Really annoying for me as well. I think deleting all past activities helps!

I'm also experiencing same issue. Gave Garmin one last chance with the 840, but they never disappoint with a bed user experience.

• Garmin Connect never works perfectly in my life! With products like Edge 1030, 820, 830 and now 840! Syncing the ride files always like downloading a 1TB files! Always have to manually syncs! Deeply considering to move to other brand for next upgrade!

Any updates or solutions on this issue? It's become very frustrating that I have to keep opening GC on my phone and keep syncing until it finishes.

For myself, I generally only have this problem on my 530 when I'm in a bad cell reception area.  From what I can tell, the Edge won't sync unless the data can be immediately transferred to the Garmin servers.  In other words, you're not really syncing with your phone, you are syncing with Garmin servers and the GC app is just a conduit and draws its data back from those servers to show you. 

There are times my ride finishes at a location with very poor cell signal and I have to wait until I drive to somewhere with a good signal to sync.

Additionally, if I ride to and from my house, at my garage the WiFi signal is just strong enough to my phone that data doesn't transfer over cell, but the WiFi isn't strong enough to make the sync happen.  If I turn off WiFi on my phone it syncs right away as it forces cellular data to take over.

Is it possible these problems are mostly happening in areas with poor cell service (assuming the ride is not ending where you have a strong WiFi connection)?

I do wish Garmin would allow a sync without connection to their servers, but perhaps it must be this way.

I have the exact same experience.  Power cycle gets it synced.