Outlook 2016 shared calendar not always updating affairs dating offer code
The shorter the refresh rate, the more up-to-date your calendar will be.
The longer the refresh rate, the less up-to-date your calendar will be.
The net result is that OWA Calendar Sharing Permission does not have an equivalent for some of the permissions on the calendar folder, and it attempts to map it to a sharing permission as best it can.
Since Owner (and Author and Contributor for that matter) have write permissions to the calendar, it is defaulting to displaying Limited Details.
It can always be moved back and the permission changes can be undone.
Events are just like appointments, except by default, they last at least one complete day.