Part of poster sized PDFs won't print

I have an HP Designjet T1100 plotter and print posters of a wide range of sizes built in a variety of software applications (AI, Powerpoint, Canvas, etc.).  I have traditionally had everyone give me their files as a .PDF in order to standardize the printing procedure.  I have always set the print size to Postscript Custom Page Size via the print utility, and used whatever dimensions we wanted out relative to size of the media (often using the media size as my custom size when not resizing).  Recently, I have started to have a consistent problem where a piece at the end of the print won't print.  This has occurred on posters created by different users using different software as well as on reprints of old print jobs that had previously printed without issue.  I uninstalled the plotter, deleted the driver and port, and reinstalled everything.  I checked for Acrobat updates.  The problem persists.

I'm sending the job over our intranet from a Surface Pro running Windows 10.

I did find that if I selected "Print as Image" in the Advanced Print Setup tab, that seems to solve the problem most of the time (not always), but it also changes the print quality.  This has become a major issue and I desperately need help!

*for what it's worth, I did replace the formatter board on the Designjet for the second time maybe 6 months ago, so that should not be an issue