Bug when having all small items

[hufkens]

Hi, I have a bug when I configure a grid with only small items. Somehow the end of the collectionview is not calculated correctly.

This is the grid scrolled down:

But there are 3 items incorrectly still below the fold. I can see them when I pull the CollectionView up:

My grid has 15 cells and it behaves like this with every number that can be divided by 3. When I add 1 big cell it works. The ViewController is a loaded from a Storyboard.

Any ideas what is wrong?