Kasa Device won't connect to dual band WiFi network if phone is on 5GHz band
Normal dual band (2.4/5 GHz) wifi AP (and mesh or router) will use the same SSID for both bands. This so a dual band client can chose which wifi band to use depending on signal strenght etc. I don't know of any modern cell phone (Android or IOS) that aren't dual band. My Pixel 5a cannont be manually steered to a particular band, can't speak for other phones.
Okay, Now the problem the Kasa setup simply will not complete if the cell phone is using the 5GHz band. Frustratingly you need to go through all the wifi network connect disconnect steps only to have the wifi hand-off to the intended network FAIL. I spent several hours attempting setup on several different Kasa devices (and on the internet) to only finally figure out this was the root of the problem. The workaround is to disable 5GHz radio on the SSID in question forcing the cell phone to use 2.4GHz. Everything worked after I finally theorized this was the problem.
Why isn't this clearly documented in help/support documents????????
I consider this to be a design flaw/bug, its a serious limitation of the product(s). I shouldn't have to muck around with my existing working and stable wifi-network in order to get your product setup.
I could (would like to) rant more, but that would require inappropriate language. Please address this serious flaw in your Kasa setup routines.