The PDF goes through different rendering paths for display vs print. It's GDI+ for display, and WPF with an XPS spool file for print. So my guess is whatever do

The PDF goes through different rendering paths for display vs print. It's GDI+ for display, and WPF with an XPS spool file for print. So my guess is whatever does PDF to XPS filtering/conversion is getting something wrong; but then it could be complicated by an addtitional bug in the print driver which is why the report says the bug depends on what printer is used for printing.