That's really weird. You've named them separately, right? If you turn on/off the plug at your location, would it do anything to the plug at your ex-wife's? If not, then I don't get it. How come voice...

If firmware is latest, contact tplink support for solution.

Are you playing live view when you phone is connected to the same Wi-Fi? Does it happen when you remotely access the camera?

Did you have the correct command? https://www.tp-link.com/en/faq-1558.html Contact tplink support to get a clue.

Test the speed in the living room, at where the extender is. Test it twice, with and without the extender. Make a comparison.

tplink camera is not compatible with Amazon Alexa.