I just started experiencing a problem with a model where hidden lines become visible only when I am panning around the model. When the view is stationary the model displays correctly. I am using shaded with edges display style.
Additionally, when I insert this particular part into an assembly the assembly then becomes infected with the same problem. This only started happening yesterday and I never experienced problems with this model or this particular phenomena before.
Attached are .mp4 videos of this problem.
I'm using SW2017 and just updated to SP4 this morning.