Microsoft fixed a bug in Outlook where selecting multiple calendars would display incorrect appointments and time intervals. Microsoft says the problem may be caused by low screen DPI or dot density, among other things.

Microsoft explains:

Topic

After the user selects multiple calendars in the calendar pane, they may notice that the wrong time slot/appointment is selected when clicking on an appointment while viewing multiple calendars. Logs where the user has full access (that are not auto-mapped) may appear incorrectly.

Possible factors include:

• Low screen DPI, or Outlook does not maximize and the window is relatively small in size.
• A calendar is added or selected in the calendar panel.
• Both working hours and working hours are shown in the same view.

The issue has been fixed in the latest Microsoft 365 channel release for December 13:

Status: Fixed

This issue has been fixed in current channel version 2211, Build 16.0.15831.20208. It was released for production on December 13, 2022.

You may find more information in the official support document Mouth. Apart from fixing this bug, the release Also addresses Several security holes in OneNote, Visio and Office Suite. The list of security flaws in the Office Suite is particularly large.