Nest Thermostat Integration - Can't link to Thermostat Control

I am attempting to connect HA to my nest thermostat. I’ve created a Google Project, Device Access Project and OAUTH credentials. However when attempt to “Add Integration”, specifying my Project ID and Device Access Project ID, along with my Google account, all I receive is a page that says “Can’t link to Thermostat Control” , “Please contact Thermostat Control if the issue persists”.
There’s no further diagnostic information. Does anyone have an idea of what I might be doing wrong? Thank you.