The error below can be seen in the Provisioning log:
SystemForCrossDomainIdentityManagementServiceIncompatible
StatusCode: BadRequest
Message: Processing of the HTTP request resulted in an exception. Please see the HTTP response returned by the 'Response' property of this exception for details.
Web Response:
{"errors":{"name.familyName":["Required property 'familyName' not found in JSON. Path 'name', line 1, position 407."]},"type":"https://tools.ietf.org/html/rfc7231#section-6.5.1","title":"One or more validation errors occurred.","status":400,"traceId":"|d760b05a-453289a6c86ca595."}

The required family name (surname) Azure Active Directory Attribute is missing from these users in Office365.
Add Last name to these users using Office365 Admin Center or Azure AD Admin Center. Then attempt to provision the user again.