After a router reset, my Kasa devices no longer appear but the favorites icons still do but ghosted. Clicking on a group shows all devices within that group as "unknown device". My Alexa connection to all my devices is still good. Kasa application is not very trustworthy. When it was working, I could not get the iPad app to recognize any devices without setting up every single one. I have over 30 smart bulbs and plugs. Why wouldn't the iPad app automatically pickup the iPhone info? Very poor. The app should automatically discover and setup each of its Kasa devices.

My TP Link 350K range extender was having problems, kept saying no internet.  I downloaded the Kasa app and tried to connect, but wouldn't until I connected the 2.4ghz network first, then the 5G.  But after going through and naming things, changing the password, the app dumped me back to the home screen with the "No Devices"

 

I can't get anything to show up, I cant connect to the extender.  I've gone through the set up 20 times, and still nothing.  It's like it wants to pretend that it doesn't exist.

Unfortunately, the Kasa app is not very reliable. There appears to be no backup of the app data on a phone that could be used to restore the previous settings. I have tried to reinstate certain bulbs via the app, and done so successfully, but then the Alexa app no longer sees them as it did before. And... I had an unusual warning on my router that one of my bulbs (a K 125) had been hacked. It was blocked from accessing the network. Not sure how this happened, but IP address of the bulb had been redirected to a known bad guy bunch in China.