First noticed a couple weeks ago while working on a large model with photoshop open with a huge file running in the background. Attributed it to maxing out the hardware. (specs on which I have no clue).
But now it’s doing it with just skp running and a simple sketchup model. And I even use “model” loosely, as this is just a flat plan drawing… nothing entered in the 3rd dimension.
The style is supposed to be “Permanent Marker Fine” but as you see, it’s just a thick pixelated line.
Thank you for including the image. That tells us a great deal.
Two possible fixes to try. First, in window>Preferences>OpenGL, turn off Use Maximum Texture Size… You may need to quit and restart SketchUp and you may need to re-apply the style.
If you don’t see any change, turn off Hardware Acceleration in the same window and again quit and restart Sketchup.