Hi, What does it show on the kasa app when that happen? How far is it from your router? If it's too far, signal is weak, and lightbulb might lose connection. Check firmware update on kasa app too.

Reset it. If you still hear buzzing noise, contact tplink support for solution.

Hi, You mean the kasa account confirmation on Alexa app? Or you are trying to register kasa account and link to activate kasa account is timed out?

Hi, Is device time still correct? How did you turn on and off the entries? You may reset one plug, configure it again, to see if problem exists.

Hi, What's the LED status on the plugs when problem happens? Are you using local internet connection? Make sure your host network is reliable. Use fixed channel and security type AES. Check firmware...

For some models, remote controll will be enabled automatically and it will not show up and you cannot disable it. To verify whether remote control is really turned on, use your mobile data to sign in...