Hello DrDan,
Thanks for reaching out here in the Google Nest Community Forum! I'd be happy to take a look at this for you.
It appears that you're having trouble adding your thermostat to the app. To confirm, which Nest Thermostat do you have? Is your thermostat already installed with its wires? If so, try restarting it by pulling out the thermostat display and ensuring that all wires are properly connected and the tabs are pushed down. Then, put the display back to its base. Once it's refreshed, proceed by adding it to the app by scanning the QR code or typing the entry key located at the back of the display.
Keep me posted on how it goes.
Regards,
Mark
