Display Mode with Parallel Lines - Wrong Shadow

Dear All,

This is a Custom Display mode with parallel lines as shadows.
But has you see on the picture there is a problem.
Does anyone know why the shadows are not matching with the edge of the surface?
Thank you very much in advance.
All my best,

Hi Mariana -On a very large scene like this it may not be possible to clean this up completely - it looks like you are already set this way but you can help some with these settings:

max video memory
No soft edges
No edge blurring