Navigation bar uicontrols are not appearing in certain devices on iOS 11 and 12, if the code is compiled on XCode 10.1.
Works perfectly if compiled on XCode 9.2
There is no issue with XCode 10.1 navigation bar. By mistake made the following change in one common place before presenting any in my UIViewController which made all the navigation bars go transparent and the text in white and the icons in white disappered.
[self.navigationController.navigationBar setTintColor:[SSCTheme colorFromPalette:PaletteColorWhite]];
[self.navigationController.navigationBar setTranslucent:NO];
Sorry for raising this issue.