Have tried connecting from Google Meet on your phone to the TV? It also has an option for TV sign-in.
Google Meet > Settings > Call Settings > Calling account > TV sign-in.
I have exactly the same problem. On my iPad, I’ve downloaded Google Meet, choose the menu options you’ve said, but them am told that “Your browser is not supported any more. Please update to a more recent one.” on my iPad. Not even sure if that means on the TV or iPad.
I just bought a QN85QN90B TV and it has the app Google Meet. It does not work. I can get Google meet to work on my IPhone. When I enter a phone number on the TV app it does not dial the number. The TV is connected to my Network and it has the latest firmware updates.