I have previously created a group assignment with multiple due dates for individual groups. I have used the default group set "Project Groups". It is now become necessary to change the upcoming due date for some of the groups. I receive the message "you cannot assign to a group outside of the assignment's group set" on all assignment dates when trying to save the assignment after changes.
Some groups have submitted the assignment and the assignment group set is still set to the default Project Groups. When attempting to add a new assign to record I can also not see any groups within the list of Assign to options. It is as if the existing assignment no longer recognizes the group set. This problem is the same in another assignment that was set up almost identically.
How can I change these assignment due dates?