Vivomove hr all of a sudden disconnected from app. Powered device, restarted phone, restarted app, forgot the device, clicked reconnect to phone. Nothing. Won't connect to app.

Did you also delete the bluetooth connection in your phone settings?

Y

Sorry, I meant the bluetooth pairung in your phone to the Vivomove HR.

Just to confirm, you are following the instructions linked below to pair your watch to the phone?