Do a complete factory reset on the device by holding the reset button for 15 seconds. Try to see if you are able to connect to the smart plugs Wi-Fi. The phone will show that there is no internet, but it should connect at least. If it does, go back into Kasa and try to add the plug again. If you happen to have another smart phone, try to set up the plug with it. One other thing is to make sure your phone is not utliizing any VPN connections.

Did a complete reset as suggested.  Tried on a different phone.  Neither of the phones use any vpn connections.  Still same result all around.  I have given up and will be returning the plugs.  Thanks for your response.