Calendar looses sync with Exchange Calendar

Greetings, jorgeoli.

While the following information is geared towards iCloud calendars, it may also help with your Exchange calendar: 

“Things to check first

1. Check the system status of iCloud Contacts, Calendars, or Reminders to check for services outages or connection issues.
2. If a reminder isn't showing up on some of your devices, make sure that your iPhone and iPad have the latest version of iOS or iPadOS, or that your Mac has the latest version of macOS.
3. Make sure that you're signed in to iCloud with the same Apple ID on all of your devices. Then, check that you turned on Contacts, Calendars, and Reminders in your iCloud settings.
4. Check the date and time settings on your device to make sure they're correct for your current location.” If your iCloud Contacts, Calendars, or Reminders won’t sync 

“iOS 13 and iPadOS or later

After each step, check your contacts, calendars, or reminders. 

Restart the Contacts, Calendar, or Reminders app

1. Close the app.
2. Return to your Home Screen.
3. Wait about one minute, then open the app again.

Refresh your contacts and calendars

To refresh your contacts, open the Contacts app and swipe down on the list. To refresh your contact groups, tap Groups in the upper-left corner, then swipe down on the list. 

To refresh your calendars:

1. Open the Calendar app.
2. Tap the Calendars tab.
3. Swipe down on the list to refresh your events."

We hope this helps! 

Sincerely.

I have exactly the same issue. Mails, contacts, reminders all keep on syncing with MS exchange. Only the calendar stops. It is clearly an issue with the CalendarAgent function of the Calendar app.

More details about what causes it to stop functioning and how to make a permanent fix, I have not.

A temporary fix is the following:

1) stop Calendar

2) stop CalendarAgent with the ActivityMonitor (it restarts automatically)

3) open Calendar

After a while, (few days) the macOS calendar will stop syncing with exchange again.

I have exactly this situation. I had been deleting my Exchange account and re-adding it every couple of days....what a pain!

To stop the CalendarAgent by command line you can use `killall -HUP CalendarAgent`. Once stopped, it will restart when you use Refresh Calendars (⌘R) in the Calendar app.

To do this repeatedly, you can set up cronjob.

At work, the uses have been using

pkill -9 calendar

You all have inspired me. Comments/questions/recommendations gladly welcomed!

MacOS Calendar.app sync to Exchange365 keeps breaking (and how to "fix" it)