My watch unconnected itself from my phone.
When trying to pair the devices, my phone finds my Vivoactive 3 Music device but then fails during the “Completing setup” phase.
For what it’s worth, I am a mobile app developer so I have tried restarting everything and reinstalling the app. Also connected the watch to my laptop and downloaded Garmin Express to install any updates. However to install updates, you need to “set the device as your activity tracker” which of course is the main problem.