The only way I have a *fairly* consistent successful bluetooth connection with my phone and my 920xt is to first unpair your device in the Bluetooth settings in your phone, then turn on location services on your phone. Then turn on Bluetooth on your phone. Then go to Garmin Connect app on your phone and go to Devices, select your device, and get ready to choose to connect.
On you watch: go to settings, select Bluetooth, turn off. turn back on. scroll down to pair mobile device. choose to pair, then go to Garmin Connect on your phone and choose to pair device. Basically, you are doing a complete reset of the connection, which works almost all the time for me.
Hope that helps someone. I hope they fix this soon. You pay a small fortune for a watch, but we have to remember HOW MUCH technology is in this little gem. I'm trying hard not to act like a spoiled rotten American :)