Forerunner 735XT and Garmin Mobile Android on a Samsung Galaxy A3 2017.
Everything worked fine until last Wednesday (March 13, 2019).
For the last two days my watch does not reconnect to the phone anymore, when a connection is temporarily lost for some reason (like walking out of the room). To reconnect I have to do some magic which involves:
* opening the Connect app
* turning location on/off
* turning internet connection on/off
I'm not sure which one does the trick, but when I fiddle with the above for some time the watch reconnects eventually.
Also please note, that once connected, the connection remains stable no matter if the app is open or not, or if the phone is connected to internet or not, or if location is turned on or off.
I do not recall making any changes and/or updates to my setup in the last 2 days, and yet the problem started yesterday.