Using New Outlook on Windows for personal email, calendar, and contact management
See this reply from Roger Bear Smith on 21 Jul that fixes the problem in the New Windows Outlook App. It seems like Win 10 or prior because my Win 11 worked.
In new Outlook.
Navigate to Settings > General > Privacy and Data > Privacy Settings.
Enable Turn on experiences that analyze your content.
Please report this to the App developers so they can troubleshoot why this somehow enables the editor to work in the App.
Maybe they can rollout a fix.