Dragging the mouse to select text randomly moves the entire sheet
When dragging the mouse to select text in a text box it would sometimes move the entire page and pasteboard to the left or right when reaching the text box frame. This is a very old, extremely annoying behavior. It exists at least since CS4.
The biggest question: why does it move at all?
In the video I was already far outside the frame when it started to move the page/pasteboard, but it often occurred to me also when the mouse pointer was just right outside the frame. I think it's when the page is zoomed in, when the page margins are closer to the window edge.