Hi
Whilst Apple has pulled back the watchOS 3.1.1 update (pending resolving an issue that affected some users), the update included a fix for dials not appearing on analogue watch faces after changing the temperature unit in the Weather app.
As your issue appears to be similar, but arises under different circumstances, I suggest that you contact Apple Support or submit feedback to Apple:
To contact Apple Support:
To submit feedback:
It may help, pending any related software issue being addressed, to follow these steps:
Restart both your iPhone and your watch:
- Close the Watch apps on your iPhone:
- Double-click the Home button, then swipe up on the app preview to close it.
- Turn both devices off together, then restart your iPhone first:
Unpair and re-pair your watch: