This issue came after this exact use case:
1- An instructor adds a new Assignment without checking "Are submissions for a group?"
2- The Instructor edits again the assigment and, for example, by mistake, he deletes the assigment Title. He also checks "Are submissions for a group?" and saves the assignment.
3- An alert comes up saying 'Alert: Please specify the assignment title.'
4- Instructor adds the title and saves the assignment.
5- The assigment has not been saved with submissions for a group.
The problem is that on step #4, the assigment configuration unchecked the "Are submissions for a group?". We understand that the alert showed in step #3 should not affect how the assigment was configured.