Ok, I managed to get it working for me using the Google Nest SDM app however I suspect that this would have worked with the normal Athom Google Nest App too so if you have the same problem then try this:
Do not enable all Google Nest permissions when adding your doorbell
Specifically these are the permissions that I use for my doorbell named “Front door”:
Note that I had to disable “Allow Homey Nest to see and display your camera’s livestream”
