Since upgrading our platform from Moodle 3.1 to 3.52+ , logs show tens of thousands of events called "calendar event update". The description follows this pattern: The user with id "[admin id number]" updated the event "[name of event]" with id "[number]"

There are over two thousand pages of such logs. The update logs refer to events in past courses that we keep for archival reasons as well as in new courses we have prepared,
but it is difficult for me to imagine how a total of 140 courses could be generating so many logs.
Moreover, by scrolling the list, I noticed that the same events are being "updated" again and again, always with the same parameters.

The logs started being generated after the upgrade to 3.52 and keep growing every day.