Hey Thiago,
such portfolio filter situation is not a bug, rather an intended behaviour: the portfolio grid in Kanso is powered by DeSandro’s Isotope plugin; it is based on jQuery, which means it works with the items already loaded on the particular page. It cannot “find” other projects which haven’t been queried via php because Javascript is a client-side language and php is a server-side language.
One solution to this might be increasing the number of portfolio items shown on the portfolio page (use the “Portfolio Items per Page” option on the “Portfolio Page” tab of the Theme Options panel). This will ensure that at least some of the items of each project type get displayed.
Sincerely,
Andrii / Satori Studio