It's about the browser stage.
<script type="text/javascript">
function fnPickedFlow(){
    return #('input[name=pickedFlow]:checked').val();
}
$( document ).ready(function() {
    console.log( "pickedFlow:" + fnPickedFlow() );
    // The first time return "one"
    // The second time return "two"
});
</script>
<input type="radio" name="pickedFlow" value="one" checked/>
<input type="radio" name="pickedFlow" value="two" />
The first time when page loads, Radio button one is selected by default. When changing the selection to two and submitting, the redirection happens. And user click browser back button (javascript:history.back()) to come back to this page, pickedFlow is pointing to one but the selected button in UI is two.
Change code add autocomplete off for each of radio button to avoid the situation:
<script type="text/javascript">
function fnPickedFlow(){
    return #('input[name=pickedFlow]:checked').val();
}
$( document ).ready(function() {
    console.log( "pickedFlow:" + fnPickedFlow() );
    // Always return "one"
});
</script>
<input type="radio" name="pickedFlow" value="one" autocomplete="off" checked/>
<input type="radio" name="pickedFlow" value="two" autocomplete="off" />
Also see:
https://forum.vuejs.org/t/radio-button-retains-old-state-on-browser-back-button/97417