I have had the Fenix 5X for awhile now.
At first, I had a hard time staying connected to Bluetooth.
I still have that problem, but my watch randomly buzzes Livetrack Ended and I see the phone say "reconnected".
I am currently RIGHT next to the phone with the watch.
I have tried deleting and readding...
Turning off Livetrack Autostart...
About the only thing that works is turning off the phone's Bluetooth.
Anything else to try?