A visible invoice is not enough
An ordinary PDF may display all familiar invoice fields but still lack structured invoice XML. OCR would infer values from the image; FakturFokus does not perform OCR or claim a scan is an e-invoice.
Ask for the source export
Request XRechnung XML or an appropriate ZUGFeRD/Factur-X hybrid PDF from the issuer. Printing an existing hybrid PDF to a new PDF may remove its embedded attachment. Forward the downloaded original rather than a screenshot or print conversion.
Inspect the separate layers
An embedded XML attachment still needs schema and business-rule checks. The surrounding PDF has separate PDF/A and metadata checks. Report a missing attachment distinctly from invalid XML inside a supported hybrid document.