This bug has been around in Revit for many many years and the only solution is to use raster processing in print setup option wish I is problematic because the result is like an image.
This is an annoying bug and I can´t Deselect “Draw MEP Hidden Lines” in Manage>Mechanical Settings>Hidden Line because in others views I would like to see those MEP hidden lines.
I remember that in Revit 2015 this problem doesn’t happened. PLEASE solve this issue in Revit PLEASE!!!!!