I am pretty sure this is related to the near and far clipping planes of the camera having changed in a recent version, which causes a crap load of z-fighting. I see a fighting even on non-coplanar surfaces, e.g. where the crawlerway mound meets the ground.
As much as I love KSP, they really don't get the basics right yet, after all these years:
Improper camera clipping planes.
Bad Shadow Cascade values.
No postprocessing stack (at least there is a mod for that).
Thygrrr's post in Visual Glitching With Crafts 1.4.3 was marked as the answer