Can't see all the content in fixed drop-down menu

[LindaTL]

Hello!

I would like to know if someone has the same problem I have, in our drop-down menu called "Productos" you can't see all the content in it. It happens only in the desktop version: if you try to access to the submenu called "Papelería > Material de oficina" you can't scroll-down over it to see the full content. If you access in the phone version you could verify that there are more options as categories. Since the menu is fixed on the website, you get to the point where you can't see more content of it. Someone knows how to fix this?

Website: tabletypc.es

Thanks in advanced!