This issue is due to mismatch with the email address in the Hub and email address in your Microsoft Tenancy. Please ensure that the email address is exact match in both systems.
Log into the Solgari Hub.
Find the user that gets this error.
Ensure that the email matches exactly how it is in your Office 365/Microsoft Entra/Active Directory. Click Submit after you have made the change.
Restart the Teams application afterwards.
If the issue persists, please contact the Solgari Support for assistance.