After grobidOrg/grobid#532 is merged, we need to pass Accept: application/x-bibtex in the Grobid fetcher (to be able to use an unmodified Grobid server). Currently, we rely on a patched Grobid server: NikodemKch/grobid@e89810b

Refs JabRef#5614 (comment)

• Header - see above (GrobidService.java line 47)
• Fix host name for calling - see Add option to parse new references from plain text using GROBID service [solving #4826] jabref#5614 (comment)
• Check DNS entry