It causes tons of glitches. I don't know, maybe it's how small the sector is or something, but it also affects the floor and ceiling flats, and whatever other linedefs linked to that sector. It's graphical glitches mixed in with my railing not showing, and the camera getting stuck.
The heights are correct, the textures are correct (unless fake floor doesn't do what I think it does), EVERYTHING IS CORRECT, AND IT ISN'T WORKING.