Issue: Person or group field is showing incorrect value after saving the item.
Ex: from the below image while creating a ticket "Assigned staff" is selected as "Prakash Arya" and after saving the item it is saved as some other value.
Cause: Cache problem with Person or group field.
Resolution: give person Email address i.e. firstname.lastname@example.org and hit "Control+k" it will resolve the user and save the correct value.