Background image rotated itself 90deg [on hold]

I added an background image inside a container that was smaller than the image. It was part of the plan. Even though it automatically rotated itself 90deg, without me touching anything (there was 3 other boxes with the exact same settings, not the same image though.). Any idea how to fix that, or what it is happening?

EDIT: Issue solved, Kyle Shrader told me to use and EXIF tool, which I did. That told me the photo was rotated 90 degree, in the metas, even though it looked fine front end. I used an exif editor and put it on Horizontal (normal value for a photo) instead of Rotated 90 CW.