White space when exporting and using on iPhone

Hi!

I am publishing an animation to be imported into XCode and used on all iPhone devices. Unfortunately when I run it on iPhone devices to test, it has a big white area at the bottom. I have tried changing the height, setting the background color to something other than white (doesnt work stays white) and was wondering if any of you know how to fix this or have ideas on what is going on? Thank you!