Header rendered in overlay appears after the scenes when used with react-native-router-flux

I am using https://github.com/aksonov/react-native-router-flux and https://github.com/GeekyAnts/NativeBase on my project and I need my custom navigation bar, so I pass my component to `navBar` property of a `Scene`, but it shows up at the bottom of my android phone's screen. My component disappears If I apply styles suggested in some issues of this and router repos and other sources I found. I searched for the code which renders the nav bar and got into this repo, to this line: https://github.com/aksonov/react-native-experimental-navigation/blob/master/NavigationAnimatedView.js#L165
It renders the header after the scenes and when I move this line upper the view I get my header on the top as expected. Is it possible to make it work, without adding any workaround on the code (as absolute positioning style - personally I do not appreciate it), because it takes a lot of time to find what is wrong and search the solution or add some section on the docs with explanation? I am new to react native, so I am not sure the most correct way. I would be very grateful if you give some detailed explanation on this issue.