Constraint to bottom layout guide with TabBar issue
I'm not sure about what happened here, but I think that this could help:
Uncheck Under bottom bar in your UIViewController properties
Hope that will help!
Nicolas Bonnet's answer of unchecking "Extend Edges Under Bottom Bar" didn't work for me. In my case the problem seemed to be that I was setting the bottom constraint of my view equal to the Bottom Layout Guide.
So, instead, I aligned the bottom edges of my button and the ViewController's view as shown below.
Select both your view to pin to the bottom and the main view:
Then tap the Align selection menu at the bottom right of Interface Builder and select Bottom Edges:
