Booklet Gutter Issue - When I print a booklet at 11x17, it causes a large white line down the center. But, when I try the same thing at 8.5x11 it prints side by side as it should. Help?

I have a 36 page booklet (each page is 8x5.5in). I have exported the booklet from InDesign as Pages. In Acrobat, when I select Print Booklet and 11x17 paper, it created a large white gutter down the center and the pages do not back up to each other.

I tried the same thing with 8.5x11 paper and they pages backed up to each other correctly with no white space down the center.

I tried again at 11x17 (size needed to print my booklet full size), and it's still causing the large white gutter. It's nearly half an inch or larger.

Help is VERY appreciated!