Hi,
The filter is working, I see the ajax request on the console. The problem is, that the results container parent is set to invisible. You have this custom CSS rule:
#resultados_home {
display: none !Important;
}..the results box is placed within this element, but because it is invisible, the results are not visisble either. Changing or removing that rule, or moving the results container to a different location will resolve the issue.