How to regenerate WO for a Maintenance program requirement that already has cancelled WO?

A maintenance program was created with a work requirement set to a 40-day interval. The system generated work orders for a 365-day forecast horizon. Later, the interval was changed to 60 days, and the previously generated work orders were canceled. However, when trying to run the program again, no new forecast is generated, and therefore no new work orders can be created with the updated interval.