All three of our plugs have had the same issue with our Amazon Echo and Studio. They worked fine in the Kasa App and they connect to the same network they always have and now if you try to turn them on via the Echo or Studio you get the error "Not responding, check network and power supply" nonsense from the Echo. I used another plug the small compact TP-Link cube style and it works as expected right away. I will see if I can check the firmware on these but that's my last resort as I have done absolutely everything else that may have been an issue. Amazon has a habit of this and I'm not blaming TP-Link at all.

They change things on their end and you never know what. It is very odd that all three of these have the same issue. Can be reset and set up fine in the Kasa App and can be turned on and off in the Kasa App but the Amazon side while seeing them says they are not working. Very frustrating for sure. Luckily I had other plugs and another multi plug that works fine. At least for now.