Xcode swift grey bar at bottom of the view, above tab bar

Question

I've got a scene in my iOS app in Xcode in swift.

The scene has a View > Scroll View > ContentView (with text fields, labels, images etc.). At the bottom is the tab bar and there is a grey area above (like another tab bar but empty).

The question is how to remove the second (upper bar)? Hope the picture clarifies:

Thanks for all the answers in advance!