Using the Calendar from https://gitlab.com/kolab-roundcube-plugins/calendar version 3.2.9.1
Roundcube 1.1.5
Set an event with recurrence, say once a week forever, and a reminder for 15 minutes prior.
The first event has a popup reminder. I hit dismiss.
The events.notifyat database field for the next occurrence does not appear to get set. So I do not get the popup reminders after the first one.