The Copy/Paste of an Event in the Outlook Calendar is no longer offered and cut off without much notice. I can confirm this in Outlook on the Mac as of 4Q-2024. This appears to also impact Windows users but they have a registry workaround to re-enable it. This is not a bug but functionality that was intentionally removed by Microsoft for reasons mentioned in their post below.
Outlook blocks copying meetings with “Copying meetings is not supported.”
This change drove me insane as I historically used calendar events to track my work and export it for hour accounting against projects. Using Tempo with Jira integration made this even easier. Before this change, I would just copy some work event from earlier and move it to a new time that had my project code and description of the project. It was a massively convenient piece of my workflow.
So, deep breath, I finally found another method to make copies of Events that was not obvious.