Can you edit layer properties?

[bbro]

I'm using Nitro Pro 9 and need to edit the default state properties for layers in a number of geoPDF files.  I can view the layer properties that need to be changed by opening the layer pane, right clicking on a layer, and selecting 'Layer Properties.'  There, I can see the default state and initial state properties, but the options to change them are grayed out and not functional.  There is no security on these documents so I'm not sure why the properties cannot be changed.  Is this not possible?