[0.3.4.1] Ghost black lines/smudges - Midori Map - Image Included

I only started a month ago, so not sure on the version this started on, but I have noticed these black ghost lines in the Midori map exclusively since I started playing.
On the earlier maps, there are also black smudges. These move with the camera and are not burnt into the terrain.

They do not appear on every level, but every one of the first 6, then on and off the ones after.

Video card: GTX 960

Image with red outlined around the general outer part.

Looks like this is a known but hard to fix graphical bug. Unfortunately, there’s not much that can be done about it by either the devs or us users.