Appointment not showing in agenda side-panel

I have a certain appointment that is not showing up in the agenda side-panel:

As the above screenshot shows, today is the 18th of January. I have an appointment called “Call Dad” that spans from 26th - 27th of January. The Agenda side panel shows items before and after this appointment, but the appointment does not show up.

The appointment is not set to private. The calendar is already set to show in agenda. Other appointments from the same calendar are visible in the Agenda panel.

Hello,
in the first place click Agenda settings - “Choose folders” to see, if you have enabled the calendar containing this event.

Thanks for your reply. The folder is already enabled for viewing in the agenda. The screenshot shows that some other appointments from the same folder (same colour) are correctly showing in the agenda.

The problem seems specific to the appointment rather than the folder or account.

Please contact me directly at wilson@emclient.com - I will send you more detailed instructions.