Can't add multiple co-authors to to metadata

I’ve invited all my co-authors, I enter one name and select the right name from a drop down list which is recognizable by NOMAD. I enter a second name separated by comma but the second name is no longer recognized:

John Smith (OK)
John Smith, John Jones (not OK)

please advise

Do not enter comma separated authors. Add the authors one by one instead: enter one author and then use the ‘+’ button, right to the author name to create a list and add the next author.

I hope this solves your issue?