I don't think delete and re-create. It is remove from quiz, then re-add. And, it won't let you do that since there are attempts. (You could delete the attempts, if that is not too unfair to the students involved.)
Quiz
Quiz Marks do not equal sum of assigned values (Moodle 3.7.1)
Keskustelu on lukittu, joten et voi enää vastata siihen.