The database reflects what the users entered at the time of making the Reservations or when registering a Guest (the computer has no way of knowing what the real source of a guest is unless it is not indicated by a user).
1. When making a reservation, your reservation agents must correctly indicate the source of the guest when entering their information (new information or from history) avoiding skipping fields such as City, State, Country, since currently several of your records show empty fields.
2. At the time of Checkin, your receptionists can (and should) review the information and Pre-assignment of room (Front Office→ Reception → Pre-assignment of Rooms) to check-in (Front Office→ Reception → Register Guest or Group) they can review that the guest information is correct and if not update it (in the Guest button), the same goes for groups.
3. Finally, your night auditors can review such information and modify them, since as auditors it is their job to verify that the information is entered correctly.
Thus, Novohit offers 3 controls. You should check if your users are doing the procedures correctly.