@ernieba1 

Hi, 
In this case, you can refer to Case 3 in the link below to troubleshoot.
What should I do if I fail to configure the Kasa device?
 

If the problem remains, please help confirm the following information.
1. Confirm if your router broadcast a 2.4G Wi-Fi network. If so, please share the Wi-Fi name, security type, and channel of the 2.4G Wi-Fi. And check if the password includes special characters.
2. Please disable the 5G Wi-Fi band on your router, and then check if your other devices, such as the phone and tablet, can detect the 2.4G Wi-Fi network.
3. Please ensure your phone has no VPN program running. 
4. If you enable a 2.4G guest network on the router, check if the smart plug can detect it when configuring.

Best Regards