How do I keep a screen always exist in Stack?

[linxianxi]

I used Stack navigator.

Actual behaviour

screenA is homePage, screen B has a react-native-webView.

1. screenA navigate to screenB
2. screentB navigate to screenA
3. screenA navigate to screenB
   The previous state of screen B disappears.How can screen B always exist in Stack?

Expected behaviour

When I navigate from screen B to screen A, screen B will removed from the stack.I expect screen B always exist in Stack.I need to keep the WebView state