Blue box stuck on main screen can't access anything else on my phone?

yes thank you so much . it was driving me crazy .. what i would like to know now is how in the world did it get there . ??? thanks again !!!!

I'm having the same problem except for when I hit the volume and power button it pulls up the options that let me power my phone off I tapped to power my phone off and it moves that option to the center of the screen for me to TAP again only at that point is under the blue box and I can't tap anything that's under the blue box what do I do

Also mines an s21 I would search for how to fix this problem but my access to my phone and it's apps are limited I was lucky enough to pull up this page and now I can't close it out if I wanted to

@kindbuddy

Try pressing the side key and the volume UP key at the same time to disable the Universal switch setting. The side key is the one below the volume key

If no good and you can access the phone go to Settings > Accessibility → Interaction and dexterity → Universal switch and disable it there.