6 digit passcode required after factory reset

I am writing to you today regarding an issue I am facing with my iPhone 11 Pro Max. I recently performed a factory reset to prepare the device for sale. However, after the reset, the phone is now asking for a 6-digit passcode, which I do not recall creating.

I have attempted to use common passcodes suggested online, such as "000000", "123456", and "888888," but unfortunately, none of these were successful.

I understand that security measures are crucial, but I am genuinely concerned and frustrated. As a loyal Apple customer, I believe this situation has created an unnecessary obstacle, especially considering the purpose of the factory reset.

I kindly request your assistance in resolving this issue. I would greatly appreciate any guidance that can be offered to regain access to my device.