Dear Android 6.0 (and higher) phone users.
If you use Android OS version 6.0(Marshmallow) and above.It brought a big new battery-saving feature called Doze mode.
Our watchface may not remain connected unless the WatchFace app is allowed to run in the background after Android 6.0.
Various information provider runs in the background on your phone and you can check the various information displayed on our watchface on your watch.
So please add your watchface app to the list of not optimized apps by the following procedure.
Start 'Android Wear' app on your phone. You can see 'STAY CONNECTED' notice on the screen.Tap 'STAY CONNECTED' button.
Tap 'YES' to ignore battery optimizations for 'Android Wear' app.
Tap 'Settings' on your phone.
Tap menu button on top-right.
Tap 'Battery optimization'
Tap 'Not optimized' and change it to 'All apps'.
Scroll down and you can find your watch face name.
This example here is 'S03 for Android Wear'.
If you have 'F05 watchface' , please find 'F05 for Android Wear' or 'F05 for Moto360'
Select 'Don't optimize'
Tap 'DONE' to complete the setup.