There is no way to create separate 2.4 or 5 GHz networks with Nest Wifi. I was able to connect the refrigerator at first but then it lost connection and now if I try to reconnect it, it says the Wifi is 5 GHz and thus incompatible with the refrigerator.
I don’t know if it is applicable to setting up the refrigerators, but it seems there are similar cases where your phone being on 5 GHz is a factor and if you can get the phone onto 2.4 GHz to do the setup it helps.
For my LG Washer, I had to disable the 5ghz network temporarily in order to get the washer to connect. Then I re-enabled the 5ghz. You should be able to disable it in the settings.
Make sure your phone/ST app isn’t on a VPN. I have seen ST appliance setup complain about 2.4GHz vs 5GHz in the past, when the real issue was having the app going through a VPN.