Hello Gordon,

this indeed has to do with students being marked as "attended". I suppose your scheduler is set up to allow only one booking (or a fixed number of bookings) at a time. If a student has made a booking, they will no longer be listed as needing an invite / reminder since they can no longer make a booking. Only once they have been marked as attended, they can actually make another booking (and can be invited/reminded).

One option would be that you mark past slots as attended, or delete them if they didn't take place.

Another option would be to allow unlimited appointments to students.

I hope this makes sense.

Best wishes

Henning