New XCode version: Sliders don't work

Hello, I was using an old XCode beta version in order to do the UI work on plugins.
I just updated to the latest version of XCode and found that editing my slider in XCode breaks it (the top one without tick marks):


If I try to drag the top slider, it doesn’t move, but the value is still updated.

In XCode, the slider looks like this:
What is that white bar?

EDIT: Never mind, it seems it’s not allowed to have bigger values on the left than on the right.
So I set the “Layout” property to RTL.