The Shopware 5 migration assistant currently does not transfer the complete invoice information to Shopware 6. The date on which the invoice was created is missing from this information and only appears on the invoice PDF. This means the DATEV extension is unable to retrieve this data. Migrated documents therefore cannot be exported.
For documents created in Shopware 5, we recommend performing the DATEV export as usual in Shopware 5 and handing this file over to your tax advisor.