The style in your SketchUp model has Profiles on and set to 3 which seems pretty heavy to me. I changed them to 1 and updated the model. This is what I see in LayOut:
And exported as a PDF:
I think it looks pretty good.
If you don’t see the same thing, you might want to look at the OpenGL settings in Sketchup under Preferences>OpenGL.
I do see a couple of other issues that although they don’t directly impact the answer to your question, will cause you problems later. First, you aren’t using scenes in your SketchUp model. Instead you are using Last saved SketchUp view. This means if you go back to the SketchUp model and make any changes, changes in the camera position will transfer to the viewport. The other thing is you should NOT be copying and pasting from SketchUp to LayOut. That results in a separate reference SKP file for each viewport. You can see there are four SKP files in your LO file. And because you’ve are copied and pasted, the references become embedded meaning the viewports are no longer referencing the original model. Editing that original model won’t affect the model shown in the LayOut file.
Instead you should be creating scenes to show the model they way you want it in the document. Then you should either use File>Send to LayOut in SketchUp or File>Insert in LayOut to get the first viewport on the page. After that you copy and paste that viewport within LayOut to create the additional ones and in the SketchUp Model panel you choose the desired scene for each viewport.
Your profile says you are using 2020.2