Mshmichaels

Working on a light plot in Vectorworks 2015 with a few sheet layers for printing. In my section viewport, one of my 5 boom bases disappears except when zooming in or out, and does not print. In my overhead viewport, I have the same issue, but it's one of 10 boom bases. I have tried deleting and replacing the bases and double checking that they are in the same layer as all the others and that the layer and its relevant classes are visible in the viewport. Thoughts?