I have installed the following in my house 1 hs100  and 3 hs220 and they connect to mi wifi no problem - I have a xfinity router which is secured and runs both 5mhz and 2.4 - under one name.

I installed 3 HS200p3 and hs210 some within 3 feet of the router - they would not connect to the wifi - very disappointing .

I contacted support and they walked me through all the same steps as are in KASA app when adding a new device to no availe - all the switched will tun the lights on and off manually. 

I am ready to return the switches - not sure why they are not connecting - if they are an older model - they were fulfilled by AMAZON.