So, it’s not a problem with OAI-PMH. It’s just a metadata quality issue. Because Crossref can’t supply or update bibliographic metadata directly (it always has to come from the publisher or an organization working on the publisher’s behalf), what we can do in these situations is pass your concerns along to our contacts at the relevant publisher and ask them to submit a corrected metadata record for that item. In this case, the publisher is Springer Nature. You may wish to contact them directly as well, for the fastest possible response.