Constantly wobbling frame.
Since I got my iMac three years ago the screen frame has jumped, wobbled and moved to the right a whole frame. CONSTANTLY! It is extremely irritating when I'm in the middle of doing something with the keyboard.
If I had suspected the problems I was to have with the so-called 'intuitive' Mac before I bought it I would have got a new PC instead. Even my clunky, slow old pc is better than this.....
HELP!
iMac, macOS High Sierra (10.13)