After changing resolution on my primary (external) display from 3840x2160 to 3200x1800, icons on the desktop can no longer be clicked, selected, interacted with. I can do sort by, and clean up by, and the icons will re-arrange, but are still un-clickable. I tried relaunching Finder but the icons still can't be touched. If I switch back to 3840x2160 I can use my desktop icons again.
Edit: it's not just icons, I cannot click ANYTHING at the right edge of the screen. Other application windows cannot by clicked in that dead zone. I have maximize Safari and now I can't return it to normal because the top window dressing doesn't appear when I put my mouse at the top of the screen.