I have bought 2 nest hubs and 1 with a camera. The one with the camera works perfectly. the other 2 connect and then about 1 hour later it says it does not have internet connectivity. If I unplug it and plug it in again, it connects and 1 hour later the same thing happens. It happens to both in different rooms in the house. where there is internet connectivity.
Chiming in to ensure everything is covered here. In order for us to eliminate any network issues and also be able to check the firmware version of your devices, could you try setting up your device using a mobile hotspot. Please note you will need two mobile devices for this setup (one will serve as a router and the other used to set up your Google Nest Hub). Please make sure to check the operating system and cast firmware version.