Grid line (D) in elevation keeps disappearing

[Quirk]

For some reason the D grid line is malfunctioning in the elevations. At one point it was two lines—one offset (so I deleted it), and now it has just disappeared. At first it was only in one elevation so I copied one from another elevation, but now it is gone in all elevations. I set up the grid lines in the plan view using the grid tool in the grid tool layer and have not had an issue in any plan view. Any suggestions will be appreciated. Thanks

[Aaron Bourgoin]

Can you verify that this gridline is perpendicular to the cutplane of the section/elevation?

[Patrick M · Accepted solution]

in the elevation/section marker settings, verify the show all is checked. I don't know what the bug is, but I can verify that a marker may be set to show all one time, and not the next time you open the file. I thought it was user error, until it happened to a file which I was the only one working on. 

[Laszlo Nagy]

You can also test what happens if you check the "Show non-perpendicular Grid Elements" checkbox. If the Grid Element shows then, it is non-perpendicular (maybe just by a very small amount.)