When i first imported the two pictures in to max the gridlines didnt show up very well. To resolve this i went back and re did the guildlines by making them thicker. This didnt fix the problem.

The lines were coming up very patchy so i went in to customize and preferences.
whilst in there i went to viewports and cofigure driver.
In there I matched the bitmap size as closely as possible in both the background texture size and the download texture size and clicked ok.

i closed the problem and reopenned it and this fixed the problem.