JoomlaQuiz on Android devices

Hi all, can't understand why quizzes are not working on android browser, they are on ios one. You can also see the same error on mobile visualizzation using a desktop browser, just click at the bottom the site version.

http://www.digiba.eu/web/index.php/it/mnu-mob-test-gratuiti-alias/mnu-mob-home-scopri-quiz-sand?device=xhtml

Can anyone help me? That's a problem!

Thanks