So, I tested this with my iPhone. I had a picture I took in vertical position. I uploaded it and it came out sideways. So I tested an idea. I used the photos app to edit the photo I rotated it sideways and saved it. Then I edited it again to rotate it back to straight then saved it. Then I re-uploaded it. That time it uploaded correctly. This seems to ultimately be an issue with how the iPhone/iPad is saving orientation when it takes the picture. It seems to do it correctly when edited and saved even though it looks correct both times on the iPhone. So, that's another workaround option.
Cheers,
Alex