It could be my sh*tty computer at its best, but here's a project file! I hope someone can fix this.
I imported one image (the image that got stretched out) and I only enabled the regarding layout.
EDIT: wait, what?? Now it suddenly works?! I added the image once more on an other layer and now it works? Okay, it's the layer, that's for sure. What should my parallax settings be?
Try to move the image from one layer to another and see what happens... :O
Also, anyone any idea why it's so big? Must be my graphics?