I'm guessing you're connecting your Nest router to your provider's router? Having 2 routers can be a real problem if you're not a tech guru. Any chance you can connect your Google Nest router directly to your modem, bypassing your provider's router altogether? Or are they one and the same thing? If so then talk to your provider.
Sorry you're having issues getting your network set up with the new ISP. I wanted to check in real fast to see if you were still having issues with that and if you saw Juzdu's reply there. If you can let us know a bit more about the setup you're dealing with, I'm sure we can sort it out with you.