Single format-related error when harvesting Geodatenkatalog

We currently have a persistent single-dataset error when harvesting Geodatenkatalog, i.e.

Feb 01 00:45:56 metadaten harvester[219205]: 2023-02-01T00:45:56.404823Z ERROR harvest{source=Source { name: "geodatenkatalog", type: GeoNetworkQ, url: "http://gdk.gdi-de.org/gdi-de/srv/ger/q", provenance: "/Bund/BKG/GDI-DE/geodatenkatalog", filter: Some("environment"), source_url: Some("http://gdk.gdi-de.org/gdi-de/srv/ger/catalog.search#/metadata/{{id}}"), concurrency: 5, batch_size: 100 }}: metadaten::harvester: custom error: missing field `MD_Format`