iOS: Going back to previous screen always waits until scroll finishes

Question

Anytime we press the back button while the current view is scrolling, we see that the button press was received (the color of the text in the back button changes) but the transition will not take place until the view finishes scrolling. This happens in every view controller of our app and it didn't function this way until recently. We don't know what we possibly could have changed to cause this problem and have been unable to find any global setting that would force this type of behavior. What is going on here?

Answer 1

Check adding your UI changes to the main queue, that would be:

dispatch_async(dispatch_get_main_queue(), ^{
    //UI changes
});