I am sorry but in your case this (select menu onchange go to url) is not suitable to be used this way.
You better set a button after the dropdown and use it with go to… action on click.
It works this way, you can see there; it’s not very elegant this solution…
You could use the updated event on the select instead of the change event. Also you can implement the query state manager to prevent the complete reload of the page.
it works fine with the update event, thks. i will try also the state manager…