Well as we said user has to score 1 marks more than the marks that are set in passing score settings of the quiz :
but in your case user "
Studente modello " has 4 marks in the " 3.2. Test Formazione generale per i lavoratori: Introduzione alla sicurezza sul lavoro e normativa di riferimento "
quiz :
http://prntscr.com/n0bzfd
If user had 5 marks then he would have the access .
But yes Im confused how the user got the access to complete the next unit or quiz if he failed at that time ?
Did you changed the passing score settings after student did the quiz ?