MaterialEditor UI may have huge performance cost when dragging the slide bar if UI scale is large

[gbakkk5951]

Resolution: 3840x2160
Display Mode: Boarderless fullscreen
UI Scale = 1.75 (default value)
When I drag the slide bar on the right side of ME UI. The studio became really laggy. And the "Render/VSync" time cost shown by FPS Counter raises a lot.
But when I set it to 1.0, the time cost is acceptable, though it still obviously raises the"Render/VSync" time cost .