When users are creating a new task assignment on a change record they have to select the service on the new assignment.
Once they save the assignment record and subsequently reopen that record, the value for the service field has been erased.
If they populate the field again and re-save that record, the value will be retained in the form.
This only happens when logging the assignment from the 'Change' object, but not when creating a new task assignment from incident, although the same form is being used.
There is no business rule that is updating this field.
Since this only happens from within the Change, but not through other business objects, the issue is not related while using the same form or business object itself.
1. Log into the AdminUI under the Administrator role
2. Select Business Object > Change
3. Select the layout used by the user role > Form View
4. Find the child panel that holds the task.assignment to determine the relationship
5. Go back to the BO, select 'Relationships' from the top and edit the relationship.
5. Under 'Update Tasks fields you will see that the Task.Service field is being updated by the value in Change.Service.
> In this case, the Change.Service field was not on the Change form it was not being selected and remained empty.
Once the assignment was created, the Task.Assignment service field was updated with the empty value.
> To avoid the empty value you can either deselect this option or set it to update 'Only When Field Empty'.