Can't go back to "No outcome" in assignment

Hi Moodle community,

On behalf of many teachers in my institution, I have a question concerning outcomes in an assignment. Once I have chosen my 3 outcomes, I can't seem to go back to the "No outcome" status when I go back to modify them.

These are the steps that I follow:

*Create at least 2 outcomes for this test

1. As a teacher, create an assignment and attach the outcomes
   
2. Evaluate one student; assign a grade and the outcomes
3. Save
4. Go back to modify the evaluation of the previous student and try to change the status of the outcomes to "No outcome"
5. Save

Result: the status never goes back to "No outcome" no matter what I do...
Temporary solution: Go to "Grades" and overwrite the status there. But if you have many outcomes, you have to find out which are the good ones.

I am missing a step? 

Thanks for the help!

Melvin