2.4GHz device won't connect to Orbi

You can find this in the Tips and Tricks at the top of this forum.  I'll repeat it here.

Try this method which works for most IoT devices that require your smart phone to also be on the 2.4GHz frequency to configure their WiFi.

1. Launch a web browser from a computer or mobile device that is connected to the Orbi network.
2. Enter orbilogin.com or 192.168.1.1 (IP address of your router's LAN port).
3. The login window opens, enter username "admin" and the password that you configured for your router.
4. Click Advanced tab > Advanced Setup > Wireless Settings.
5. Uncheck the box "Broadcast SSID" for the 5GHz frequency and click Apply to save the settings.
6. Confirm that your smartphone is connected to the 2.4GHz frequency. If it is still connected to the 5GHz frequency, then "Forget" the WiFi network for your SSID, then reconnect to it and enter your SSID password. Now your smartphone should be on the 2.4GHz frequency.
7. Try connecting your IoT device to the Orbi network per its setup instructions.
8. If it works, re-enable the broadcast SSID option for the 5GHz frequency.
9. On your smartphone, turn WiFi off and back on again and it should reconnect to the strongest signal.
10. If your smartphone did not reconnect to the 5GHz frequency, then "Forget" the WiFi network again for your SSID, then reconnect to it and enter your SSID password.