Devices that use an External Print Controller to pre-process jobs before they reach the printing device can cause limited information back from the printer through SNMP. The External Print Controller is usually the point of entry and exit for network communication instead of the devices internal NIC card.
In some cases, there may be less information available from a device connected with an External Print Controller compared to one without one. Even limit available supply reporting allowing few supplies to report back.
Some common manufacturers that use External Print Controllers for example: