How to solve multiple duplicate routing pages

### Version
Tell us which versions you are using:

"react": "16.9.0",
"react-native": "0.61.3",
"react-native-router-flux": "^4.1.0-beta.5"

### Expected behaviour
Page from A to B

Then there is a button on page B to enter the new page B repeatedly

page：A->B->B->B->B->B->B

The expected result is that I can return to page A after the last page B returns 3 times

### Actual behaviour

The actual result is that all pages B are returned before returning to page A

How can I return to the homepage after opening multiple duplicate pages and returning 3 times?