[Linux LEAP 15.1][mariadb 10.4.3][C API] The UTF8 characters are not handled as before (10.2.9)

This C source code extract is expected to execute a query... but even if I change the name of the table from "Localités" to "Localites", the program no longer display the utf8 characters as the database could when I execute the same query in command line. This post The situation "before" gave those results that were expected: Expected situation I really don't know how tell the client (as the server respects the unicode) to display the datas as this program did since upgrade :{