Problem with browser back button and filter

Hi, problem..
if i set filter first time of category is ok https://www.danielebeccaria.info/sobel/tappeti-sobel/, then i click on a single product to see image and description and then i click back on browser the plugin show uncorrect result, different from the first filtering (show zero of other category)

thanks

The page I need help with: [log in to see the link]