This can happen because of the restrictions QuickBooks Online has placed on its character usage. The QuickBooks Online Customer API states: the DisplayName, Title, GivenName, MiddleName, FamilyName, Suffix, and PrintOnCheckName attributes must not contain colon (:), tab (\t), or newline (\n) characters. There are other sync rules associated with BQE CORE-QuickBooks Online integration. Check CORE Help Center for details.