Can't return tickets in a subscription

We have recently had an issue with a few orders that aren't allowing us to return subscription seats. We can return everything for this year, but the tickets that are for 2021 aren't returning, even though everything is ticketed, seated, and printed. We tried returning it two ways, by using the seat map and when that didn't work ("this seat cannot be returned") by using the Return button, which was grayed out. Has anyone experienced this and if so how did you fix it?