Courses Quantity – quantity in the basket doesn't show in checkout


i have CoursePress Pro connected through woocommerce (this is a mandatory fact, for what we need we can’t use marketpress), and i’ve noticed that when i increase the quantity of the product in the basket, it doesn’t then increase in the checkout page.

The website is supposed to be live soon, but we need this feature, an user must be able to book the same course in more quantity.

Is there an easy way of doing it without changing the plugin file? if so, could you please explain me what i’m doing wrong?

If you need access to the website i can grant it, just let me know.