If you experience problems with the myatmo Apple Watch app or with watch complications, then the following steps usually help:

• delete myatmo from the paired iPhone
• restart iPhone and Apple Watch - this is very important!
• reinstall myatmo on the iPhone and the paired Apple Watch
• start the myatmo iOS app at least once and configure your access before you use the Apple Watch app - this is very important!

This will reset and reinitialize all settings, as well as all the connection settings between the myatmo iOS app and the WatchOS app.