Are those displays in scaled mode? Scaled displays tend to perform badly on integrated graphics, and suck up memory, because it has to render a 2x or 3x size in

Are those displays in scaled mode? Scaled displays tend to perform badly on integrated graphics, and suck up memory, because it has to render a 2x or 3x size internally and then scale down for every frame. Running something that updates the screen constantly, like zoom, probably exacerbates that issue.