Thanks @Eskimo.. You saved the day. Was debugging who is observing the state. Got to know GoogleTagmanager and Firebase Performance SDK is reason of crash behind the frame 3 and 2.. I removed Performance SDK, The Crash is not replicable now. Also, I reverted GoogleTagManager (7.2.0) to GoogleTagManager (7.1.4) This case also the crash is not happened. Moved to production with these changes which resolved this crash. Thanks for ur reply @esikmo & iijjj 

There are some misunderstandings, Few mentioned like, UINavigationBar.appearance().barTintColor can change navigation item color as well. But below code helped me out to change the Done button color UIBarButtonItem.appearance().tintColor = .green If some one stucks on it. it may help. Thanks.

This will work. It will change the done button color UIBarButtonItem.appearance().tintColor = .green