Feedback type decides when students see their marks and comments.
Setting it
Open the lesson and click the three dots in the top right. Feedback type is in that menu.
Instant. After every question.
On submission. When the student submits the lesson.
On return. When you return the lesson, so you can moderate the marking first.
For anything that counts, use On return. It gives you a chance to check the AI marking before students see it.