(OJS version 3.1.2.0)
Upon validating OAI-PMH data on http://validator.oaipmh.com/ with http://historiaregional.org/ojs/index.php/historiaregional/oai (the journal in question), though ListRecords for OAI_MARC, MARCXML and RFC1807 work correctly, OAI_DC provides no response at all, as if it had timed out.
Indeed, when checking directly with http://historiaregional.org/ojs/index.php/historiaregional/oai?verb=ListRecords&metadataPrefix=oai_dc it takes several minutes for the site to provide the XML data.
What could be causing the delay for this Dublin Core format in particular?