I also notice funny business with updates going on with my computer, despite trying to stop updates without notification and approval by me.
The latest problem is when I first turn on my computer and the main screen has loaded it cycles for some time before I can open any program which tells me you are correct and MS is doing something in the background when I boot up. I've tried making some changes but nothing helps.
Anyway, I also shutdown using a power strip, but after shutting down with the start button. I suspect MS might be sending updates when the computer is off but somehow they load when I boot up each day (is that even possible?).
One thing you might try instead of shutting down with the power strip is to first do a hard shutdown by pressing control+alt+delete a few seconds, then turn off the power strip. Somehow that feels safer to me, but not sure.
I am also tempted to go to a Mac but dread the learning curve, LOL.
Newly