Level Display Settings Lost When Drawing Saved, Closed and Re-opened


I have a drawing with multiple saved views on the sheet view, each with differing level display settings (ON or OFF) for the references that make up the drawing.

With these all set up correctly in the level Display dialog box, I save the drawing (and the settings, just to be sure!) and close the drawing. However, when I next go back into the drawing, whilst all other edits have been saved correctly, as you'd expect, the level display is completely different, with most references now set to Display OFF and shown grey in the Level Display dialog box. It is easy enough to restore, but a waste of time and a worry if someone else opens the drawing and is unaware of this problem.

Has anybody else seen this issue and, if so, how did you resolve it?

Thanks for your help.