[keycloak-user] Stored ? characters when some non-ASCII characters are input in Keycloak 2.5.5.Final

Hi, I have an installation of Keycloak, version 2.5.5.Final, with MySQL. If a user with odd characters registers, those odd characters are substituted by ? characters, e.g. the name Sůsa will be stored as S?sa. I think this bug was already fixed. Any clue? Thanks.