Hajj is already obligatory on a person, but they expressly intend voluntary Hajj. What happens in the taught exception?

Four Types of Timed Worship: The Role of Time

• It is voluntary Hajj; the obligatory Hajj is not discharged
• It must count as obligatory Hajj despite the express intention
• No Hajj can be performed within its season
• The obligation disappears because voluntary reward is greater