Garmin edge 840 not syncing

This is frustrating... The Edge 840 is perfect, except for the really bad syncing with Garmin connect. 1/2 rides will not upload unless I connect it through a usb cable to the computer. I've tried removing the device, resetting phone, GPS, everything... But still, after a few days it always comes back to the 1/2 ratio. 

Is there a solution to upload rides? Other edge devices had an option to upload the ride trough the device... 

Help.