Can you try power cycling your router, along with your Google homes?
Also for the light command, the tp link switches may be labeled as "lights" according to the GH.. you might need to change them to outlets or something along those lines. I have some tp link plugs in my living room that happen to control floor lights , and If I don't say which light to turn on or off they all do.
@Ashepherdson, thanks for helping.
@DB_Pita, this is not the experience we wanted you to have, let me help you. A few things: were there any recent changes made? Have you had the chance to take on the steps above to see what happens? It would help a lot if you could do a sequential reboot first:
Also, make sure that your smart lights and your Nest Doorbell are working on their native app and tell me how it goes.