Appointment moving from Calendar to deleted items

[Oliver McErlane]

Hi,

We have a desk booking app which allows staff to book a desk in the office. 

It sends the staff member and email with a .ics attachment which they can save to their Outlook Calendar to let others see that they are in the office. 

Sometimes this appointment moves from the Calendar to deleted items without manual intervention. 

Anyone any ideas why this would happen or have seen this behavior before?

Thank you for your time,

Ollie 

[#2]

This is example content of the .ics file, if this helps.
The appointments still randomly disappear. Strange?

BEGIN:VCALENDAR
VERSION:2.0
BEGIN:VEVENT
UID:email address removed for privacy reasons
DTSTAMP:2022-04-21T13:14:03Z
ORGANIZER;CN=email address removed for privacy reasons:MAILTO:ID:email address removed for privacy reasons
DTSTART:20220830T080000Z
DTEND:20220830T200000Z
SUMMARY:Bedford Square - Desk: 4-72
DESCRIPTION:If you are not going to use the desk you have booked, as a courtesy to your collegues please cancel it by going back to the app, click on the top right icon, select the date you want to cancel, and confirm by pressing "Cancel Booking"
LOCATION:Bedford Square, Bedford Street, Belfast
GEO:54.594238,-5.931504
X-MICROSOFT-CDO-BUSYSTATUS:FREE
BEGIN:VALARM
TRIGGER:-PT24H
ACTION:DISPLAY
DESCRIPTION:Reminder
END:VALARM
END:VEVENT
END:VCALENDAR

[#3]

Are you sure someone isn't deleting it?

If you are using Office 365 Exchange online, you can enable auditing.