Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hello C-Net Admin,
Based on the error message you shared above, as far as I know the problem is related to the user object was synced from your local AD via AAD Connect, and if you directly edit the user's mailbox organization information from Exchange Online, you will get this error message. And it not affects with the user directly created from online side, thanks.
Generally, for the AD synced user's information must be updated from local AD side, and then sync the changes/update to Microsoft 365 Azure AD/Exchange Online after that. So if you want to update the manager etc information for the organization structure, please go to your local AD server > tools > Active Directory Administrative Center > find the AD user you need to update > right click it > properties > then update the manager or other information under Organization section. Once you successfully update the organization information, please wait for next sync cycle or force a DirSync via AD powershell Start-ADSyncSyncCycle -PolicyType Delta then wait for some minutes go back to Exchange Online mailbox organization information page to see the result. Please note, this changes may take some hours to across the whole tenant and make others to see the updated information, thanks.
Please feel free to let me know if you got any further updates, thanks.
Best Regards,
Oliver