iPad calendar keeps losing appointments

Hello AlisonB61,

Welcome to Apple Support Communities!

We want to help ensure your events are saving properly. Make sure you're using these steps to save your calendar events:

"Add an event

1. In Day view, tap  at the top of the screen.
2. Enter the title of the event.
3. Tap Location or Video Call, then enter a physical location or tap FaceTime to enter a video link for a remote event.
4. You can also copy a FaceTime link you created or received and paste it in the Location field. See Create a link to a FaceTime call on iPhone.
5. Enter the start and end times for the event, the travel time, invitees, attachments, and so on. (Swipe up, if necessary, to enter all the meeting information.)
6. Tap Add."

This Apple Support page has the full details: Create and edit events in Calendar on iPhone - Apple Support

Double check to confirm your events are properly created.

If they are still being removed, please reach out to an Apple Support Advisor for further assistance: Get Support

We hope this helps as they will be able to further investigate exactly what might be causing this.

Cheers!