These are all IP Address issue. In short, your watch also needs to be connected to the internet depending on your connection type -
In Short, goto GOOGE PLAY, you will notice your watch is obtaining a new network connection with your WiFi or other, once you are in, go straight to FACER app, switch faces and you will see it works, but only for a period of time.
2 fold issue, Huawei watches always loose IP until they are called tor. Second issue is Facer is depending on this IP vs just using Bluetooth.
To test this, I wrote an app, served the faces on my personal computer and changed the connectivity and all works perfectly all the time.