Hi Robin,
I truly appreciate your effort in finding a resolution. I believe that many users may encounter similar issue, and your case could serve as a valuable reference for them.
Therefore, I would make a brief summary of this post so that other forum members could easily find useful information here:
Issue Description:
Outlook – Ctrl+V and Ctrl+C not working
Assessment:
- Update the latest Outlook version
- Check for Add-in Conflicts
Due to this situation, personally, I’m totally agree and understanding the convenient of the old . It definitely great improvement to the current availabilities of Microsoft 365 apps. In that case, I sincerely recommend you go to Feedback community to vote this similar feedback: (find out similar feedback, if not provide the feedback forum link Ideas · Community). Our product team is in charge of the site, and they constantly check customer reviews and feedback, The higher votes, the more attention the related team will pay on. And a lot of the features are developed and improved based on customer feedback.
As other users will also search information in this community, your valuable vote will definitely also help other users who have similar queries easily to find the correct channel and useful information more quickly.

Greatly Appreciate again for your patience and understanding.
Best Regards,
Allison - MSFT | Microsoft Community Support Specialist.