In kernel/private/classes/clusterfilehandlers/dfsbackends/mysqli.php, in the method _checkCacheGenerationTimeout(), a misplaced semicolon causes the method to return true in every case.

if ( isset( $row[0] ) and $row[0] == $generatingFileMtime );
{
    return true;
}

A proposed fix can be found at https://github.com/ezsystems/ezpublish-legacy/pull/651