I've just upgraded from a Fenix 3 to a 5S and am having some issues.
Firstly I've tried to upload some courses to my watch in exactly the same way that I did with my 3, from Garmin Connect Mobile on iOS via Bluetooth, but they don't show up on my watch.
Secondly Garmin Connect says that there are sync issues (although helpfully fails to state what) with a red exclamation mark, but I've just checked and an activity does sync to the watch when complete, so this is at least working.
I've also just tried to install the Running Power Connect IQ app, and got a Device Communication Error notification...
Any thoughts or ideas gratefully received.
Richard ciq.forums.garmin.com/.../1352878.png