When I look for an existing user in the journal, it does not appear as a result when the journal is in the Spanish language, but when it is in English it does give me the user as a result.
I realize that if the Family name has characters like ñ or hyphens it doesn’t give me search results.
This is an open issue here: Must use accents when searching by author/reviewer name in editorial backend · Issue #7140 · pkp/pkp-lib · GitHub - identified as an enhancement that will hopefully be implemented in future versions of OJS. Since 3.1 is no longer supported, you would likely have to upgrade in order to take advantage of this when it is eventually implemented. It’s not perfect, but I tested in 3.3 and it was a bit better, but not perfect using the ñ character did produce some results (but also included n characters).