Using New Outlook on Windows for personal email, calendar, and contact management
Hi Andy,
Known issue.
Via https://learn.microsoft.com/en-us/answers/questions/5972491/outlook-lost-contacts
Press Windows + R, Paste
%localappdata%\Microsoft
and press Enter.
Delete the Olk and OneAuth folders.
Restart Outlook.
This only removes temporary Outlook data that will be recreated automatically. Your emails will remain safe.
Try saving the contacts again.
I look forward to hearing from you to get the results of the troubleshooting.