printing 24x36 pdf results in blank 24x26 pdf?

When attempting to print a Floor Plan drawing on 24x36 size sheet at 1/4 scale the following occurs.

My drawing settings say ArchD
My Adobe Preferences indicate ArchD

...and yet it says wants to change settings to 0,0 which results in a blank 24x36 pdf document.

This doesn't happen with 8.5x11 or 11x17  

what am I doing wrong here? I need to be able to make 24x18 and 24x36 pdf documents/
 

I can't see a reason from your screenshots why it doesn't work while the other formats do.
A fault of the Adobe pdf printer? Can you try to set the size for Arch D manually in inches (Custom)?

Why don't you use LibreCAD's own Export to PDF?
Make all the necessary settings in Print Preview as if you were to print to paper, then go to File - Export - Export as PDF. Stay in Print Preview mode.