The pre-built quizzing function is designed to make a selection (can switch choices before submitting) and then submit. At this point, the person is directed to the feedback appropriate to your choices.
I misread what you wanted to do since you said the submit button you created isn't working.
In your case, you can add the submit trigger to all of the radial buttons. It's a bit unorthodox but the selection would automatically be submitted and they'd go to the feedback layer. In your case, when it's unlimited they'd just toggle back and forth until they eventually make a correct selection.