One trick that might help: Turn off (pull the power) of the first point ("point 1") you managed to set up. Then set up the last point ("point 2"). If success, turn point 1 back on, and both points should be connected.
Below is my usual reply with more tips.
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Here is some general advice if you're having problems with adding additional units to the network.
The general set up guidance walk you through how to add additional units:
• https://support.google.com/googlenest/answer/9548301?hl=en
If you're using an iOS or iPadOS device for the setup, see the following:
• https://support.google.com/googlenest/answer/12961504?hl=en
Make sure "HTTP Proxy" is set to "none".
• https://www.expressvpn.com/support/troubleshooting/disable-proxy-safari
And make sure "Private IP Address" (Mac randomization) is disabled.
• https://support.apple.com/en-us/guide/security/secb9cb3140c/web
• https://support.apple.com/en-us/HT211227
For whatever device you use for setup (iOS, iPadOS or Android), make sure any VPN are disabled, and that Wi-Fi and Bluetooth are enabled. Also make sure to use the latest version of the Google Home app.
Some other tips that can help:
• Tro to restart all working Nest Wifi units by using the "Restart entire network" inside the Google Home app -> Wi-Fi (icon) -> Network settings -> Restart entire network. Then try to set up the additional unit.
• Place the unit you're trying to add close to the primary unit during the setup process. When setup is done and unit has updated itself and rebooted, unplug its' power and move it where you want it.
• Power off all other units but the primary/main/master unit. Try to set up the additional unit. If success, let it update and reboot before powering on all the other units. All units should now come back online.
• If the additional unit also has ethernet ports, try to connect its' WAN port to the primary/main/master unit's LAN port with an ethernet cable during setup.
• IPv6 has caused trouble in the past when adding additional units. Try to disable IPv6 in the Google Home app -> WiFi (icon) -> Network settings -> Advanced networking. Keep it disabled until unit is added. Enable IPv6 again if you need it.
• If the unit you're trying to add isn't brand new, make sure it's factory reset ( https://support.google.com/googlenest/answer/6246619?hl=en ) and ready for setup.
• Try the setup process from a different iOS, iPadOS or Android unit. Make sure to use the same Google account inside the Google Home app.
• Make sure not to run double NAT, as it can cause strange problems and performance degradation ( https://dongknows.com/double-nat-vs-single-nat/ ). Disable the routing functionality, DHCP, firewall and Wi-Fi in any equipment in front of the first/main/master Nest Wifi unit.
• Don't mix the new Nest Wifi Pro with older Google Wifi and Nest Wifi, as it's not backwards compatible.
Be aware that Nest Wifi units are made for different countries/regions in order to comply with Wi-Fi regulations (frequencies, channels and signal strength). Mixing units made for different regions are not supported. The Google Home app should warn you if that's the case, but it doesn't always do that.
I don't work for Google.
