WooCommerce Multi Currency – Currency Switcher doesn’t display properly on iphone 6

I have WooCommerce Multi Currency – Currency Switcher installed on http://www.wordpress5.kodografia.com/. It works properly on desktop, but it doesn’t work on iphone 6. Once I click on the “plus” button to change the currency, a light white overlay covers the whole screen and I cannot click on anything. I can send screens, send me an e-mail.