Custom hatch pattern display / print / PDF conversion issue in TrueView

Hello,

I have a .dwg which was created in AutoCAD 2008. In that drawing are some custom hatches.

I'm currently trying to view this drawing in TrueView and convert it to PDF.

The finshed drawing layouts are in paper space, with multiple viewports displaying the stuff that is in model space. But the custom hatch (drawn in model space) appears solid when it ought to be a series of stripes. If I zoom in, the hatch suddenly becomes striped as it is meant to be.

However, when i print or convert the layout to PDF, the hatch appears solid.

I also have the same hatch in the key, which is in paper space on each layout. It displays, prints and converts to PDF fine.

Any ideas why the model-space hatch isn't displaying, printing or converting properly?