I don't know how to explain this easily, but I use two-page view for easiest viewing on my Mac, and in the PDF I'm using, most pages (including the first one) are in portrait view, while some are in landscape, but the landscape ones are showing rotated into portrait mode, meaning I have to angle my head to read them or rotate the whole view (which also rotates the portrait ones)... example:

My coworker's displays properly, but we can't figure out how to get mine to do it:

He has Pro by the way, and I don't need Pro just to view PDFs.