Slight Graphical Error

[ReddRumn]

Was testing a WAD I'm working on and noticed that a texture is weirdly showing through another. I've attached an image that shows the problem.
TOP: GZDoom Builder
BOTTOM: Zandorum 3.0

 

Is this an issue I can fix, or something with Zandorum?
Thanks for any help.

[scifista42]

Make at least 1 unit height difference between floor heights on each side of the line, or at least 1 unit brightness difference between sectors on each side of the line, or use "Clip middle texture" flag on the line if you're mapping in Hexen format or UDMF.