Microsoft form how to get text box answer to add to overall percentage

Hi. I have a form with multiple choice questions and text box questions. The multiple choice are autograded and contribute to the percentage score at the top of the page when I look at responses. When I add a score to the text box answers and they turn correct, why doesn't that contribute to the over all percentage? Or how do I make that happened. For eg. There are 10 multiple choice and 10 text questions. If they get all the multiple choice correct, the auto calculated percentage is 50%. If I score all the text box answers that make them correct, I want it to show 100%. But it remains at 50%.