First page only printing as a mirror image, but only when printed on Tabloid size paper.

When I print a document directly from illustrator, the first page I print - and only the first page - is printed flipped, as a mirror image. It doesn't matter which artboard I print - the first page out of the printer is flipped horizontally. 

I tried fixing the emulsion. When I set it to "down" it prints everything in mirror - except the first page, which is then printed normally. So this is what I do when I just need to print one page. 

The plot thickens: while I was making tests to show you all, I found out that it only happens when I print on Tabloid-size paper (11x17). The problem did not happen on 8.5x11. I haven't tested other sizes yet, but I usually print on Tabloid for work. (Ignore the black grid on the paper - I used scrap for these tests). 

This only happens in Illustrator and no other program, so I know it's not my printer. 

Let me know if you need more screenshots/references than what I provided. Otherwise, anyone have any insight?