Automatic termination of Calendar no longer work after seval days running on new system

I recently brought a new MBP which was set up as a new device. However, I noticed that after several days, (if it was not after I added exchange accounts next to the iCloud one, but those did not have calendar account enabled) the calendar does not terminate itself after closing all windows and switched to other apps. I read there should have this "automatic termination" behaviour if no ongoing process exists. Just should it be as reminder is doing.

So I come to this community to see if there's a solution here, or was the problem triggered by the exchange account? These accounts have only mail enabled, no calendar.