It is possible that one position too many may be invoiced and thus a reminder is issued automatically. You have the option in bexio of re-editing the invoice from which the reminder was generated. This also edits the reminder.
To do this, open the desired reminder and click on the status action "Edit invoice again".
Then edit or remove the desired position and click on "Invoice is issued". If you now create the reminder with letterhead, the position on the reminder is also changed.