Responsive mobile menu not working in mobile devices

Hello, I′m using https://www.wordpress.com for making the website (online tool). I′m not sure of the version.

Mobile menu was working some days ago but nowadays that menu stopped working alone (when I try to go inside of menu it is not opening) and I didn′t touch any other configuration button.
I searched other websites that uses this theme but they have the same problem.

Thank you very much for your theme and your support!