Height of search bar is not changing when we hide scope bar.

I am facing an issue with scope bar in UISearchBar. I am showing scope bar with three scope button titles. In one scenario I want to hide scope bar. I am using [searchBar setShowsScopeBar:false]

Issues that I found are as follows

1. scope bar goes behind search bar
2. Height of search bar is not changing
3. I used [searchBar sizeToFit], it is also not working.
4. if I use searchBar.scopeButtonTitles = @[]; , scope bar hides but height of search bar does not change.

I test my code on iPad having iOS version 11.3