Problem with “Events are bookable for up to”

Hey there.

I’m trying to keep my users from booking too many classes in advance.
I have made a recurring event that are our classes.

I found that editing my booking form, then calendar, allows me to just do that with the option “Events are bookable for up to”

The description says: “Set the end of the availability period. E.g.: “30”, your customers may book events starting within 30 days at the latest. They are not allowed yet to book events starting later.”

So I entered 45. But when I log in as user, I can still book classes that are 60, or 90 days away.

Is this a bug? Am I doing it wrong?