View being unintentionally resized when appearing

[petard]

One of my view controllers has a UILabel which is horizontally centered and has a fixed constrained from the top of the view controller:

When running the app and swiping to said view controller the UILabel will somehow rerender, i.e. the UILabel is initially show much closer to the top and then jumps into the right place. This only happens on the first view, afterwards it is always in the right position.

Oddly this only happens when a view is tied to the top, when I add another UILabel that has only constrains to the bottom or to the sides everything works as it should. Same for elements that are horizontally or vertically centered or collection views that span the whole view.

Any ideas what could be causing this or how to fix it? The closest I could find was described in this SO post

I'm using XCode9.

[cronjob4]

I am having this issue too. It appeared on iOS 11 and I don't think there is a clear fix yet.