When creating recurring / repeating events, all events I create get the same cutoff date (date when bookings are not accepted anymore) as the first event. This goe for the current version of DT Register 3.1.1 and I also saw it in 3.0.9. Unfortunately took some time to understand why I did not get bookings to my events. So if you other users of DT Register have recurring events, it might be worthwile to check that users are able to register to them.
When the function was created, the system worked correctly so that the cutoff date for each recurring event was the same amount of dates before the event as for the first event.