One of the WildFly users reports in this forum thread https://developer.jboss.org/thread/271498 that the application runs into an issue trying to populate data in a database via the database initialization scripts configured via javax.persistence.sql-load-script-source property, for UTF-8 charset content.

Reading the JPA spec, there's no specific mention of what encoding is expected/supported for such files, so I don't think this is a bug, but I think supporting UTF-8 (apparently the JPA provider in GlassFish does) for such files would make sense.