I just had this issue with the google home whereby I removed the wrong smart light bulb from my google home and now I'm trying to reconnect it and add it back to my home but I am unable to. I hope there is a solution for that so that I can add the smart light bulbs back to my google home.
Sorry to hear about the troubles you’re having with your lights connecting with the Google Home app, I’m sure it’s confusing, but I’m happy to provide some clarity.
I have sent this information over to our engineering team and they ask that you provide them feedback through the Google Home app to them. They suggest including the keywords, "#Lights" along with the name brand of the lights and a short description of what you're encountering.
Have a great day.