iOS problem with screen resolution?

So my app is up and working on the Playstore since one month, however I am still struggling to get it on apple.

It got rejected with this issue: - Your app was not optimized to support the device screen size or resolution.

They attached this screenshoots, appearently the bottom part of the screen appears black and blurry

I have absolutely no idea what's happening. I made a test on my old iPad, an iPhone 4, and 5, and everything went fine. Here is the screenshot Apple sent me, I resized it in order to be able to upload it here. The original size of the image was 2048 * 1536 witch means the error was on an iPad air.

PS my apologies for the terrible english.