I changed my student's per lesson fee, how do I stop the old fee from showing up on new lessons in Duet?

1) Check the calendar events. The event Cost field overrides the student’s profile fee. Resave the series with the new cost. Note – if any events were edited and saved “for this instance only” then they were removed from the event series and will need to be edited separately since they are no longer apart of the series.

2) Once a lesson is invoiced in advanced (scheduled charges) the scheduled charge is entered in the transaction log and also in the event cost field. So if the teacher changes the student profile fee, he will still need to edit the cost field on the calendar events to be blank again.