Background bug?

Not sure what this would be truly classified as so I'm gonna go with bug/graphical error, I suppose. Anywho, I guess I'll provide a brief description.

Location: The Alpha Zibal 86 System > Alpha Zibal 86 IV a (Moon / Small / Lvl 1)
Coords: x 86527219, y - 90601864

In my short time there I experienced what I can only assume to be a graphical error (of sorts). Upon traveling to the left a short ways (strictly on the surface) I noticed that as I began to go further down/left the background began to cut abruptly, with no smoothing or transitioning to the lower terrain background. I'm not sure if this change is supposed to happen in a smoother manner or not, as you go down in depth, but it has never really been a problem that I've noticed. Either way, I figured I would at least bring it up, even if it was nothing major. In the pics below you'll be able to see the cut to the bottom left of the screen cap.

Right before the cut:



And the cut itself:



By the way, I find uploading pictures here to be a bit finicky so if there's a problem viewing the whole image let me know.