ios - UISearchController not responding -

i have uisearchcontroller on navigation bar by:

navigationitem.titleview = searchcontroller.searchbar 

and have

definespresentationcontext = true 

now problem first time when go activity having uisearchcontroller, works fine. but, in app sidemenu if go activity , again go activity containing uisearchcontroller pushing navigation stack, search controller not work. here doing:

let a denote activity containing uisearchcontroller

1. go a. works fine.
2. go other activity.
3. go a pushing again , not popping back. uisearchcontroller not respond. not responding mean searchbar not respond touch.

i know should pop cannot app. can problem?

try setting definespresentationcontext no on first view controller present new 1 on.