We just switched to Verizon Gateway / Router, and now none of my Amazon smart plugs are recognized on the Wifi. I tried following the router update advice in older discussion, however the menu has changed and can’t disable SON as suggested.
Suggestion to disable SON is now out of date if not outright incorrect advice.
There is a new IoT access point could be enabled to broadcast a -IoT SSID on 2.4GHz. You could connect the "smart" devices to this wireless radio, which is independent of the main wireless radio.