Jun 03 2020
This issue "Unable to edit Contacts, Appointments, Meetings, or Tasks within Outlook" has resurfaced again. The fix was applied in June 2019 here https://support.office.com/en-us/article/unable-to-edit-contacts-appointments-meetings-or-tasks-with...
I have tested this on the latest version of Office 365 Outlook. Is there a known bug?