Styling issue on Divi theme (ElegantThemes)

Please take a look at: http://e-koncept.com.pl/sklep/produkty

This page is messed up – sidebar is not on the side but under products.

Now choose a category form drop-down and everything is fine.

How can I fix styling to make it always look good – like in particular category?

I am using Divi theme from elegantthemes.com

Thank you for your assistance.