Calendar entries don't stay


Have got the latest version and have noticed that now when I put a new reminder into the calendar it does not stay. e.g. I tried to put a reminder for a concert which has moved to April 16th 2022 in and it just will not save it.
If I shut the program down and re-open it. It is no longer there. All other entries remain. Please help.


If the event is saved in a read-only calendar, you will not be able to edit it with reminders.

So calendars someone may have shared with you, or those added as Internet Calendars.

Hi, was the standard calendar. Not read only or form the internet. Initially I changed the dates of a pre-existing entry. It jumped to the new dates, but then disappeared. Re-creating the entry has not helped.