Whether the elective homework is not submitted on time will fail depends on the importance of the homework.

If this assignment is completed, and the teacher has informed in advance that it accounts for more than 60% of the grade and will not accept overdue assignments, then it is likely to fail.

However, if this assignment is only a normal assignment with a very small percentage of scores, then you can contact the teacher, explain the situation to the teacher, and make up the assignment in time. Generally speaking, you won't fail.

I hope my answer can help you and make you satisfied.