Scroll behaviour in vue router not working firefox

Hi

i am facing a issue with scroll behavior which not working in firefox. But for firefox i am using alternative method to move to the position on top if user navigating from the top of any page.

Its working fine in chrome, edge but except firefox.
scrollBehavior (to, from, savedPosition) {

  if (savedPosition) {

    return savedPosition

  } else {

    return { x: 0, y: 0 }

  }

},

  routes: routes

});

my alternative method is mention below. I dont want to use this.

mounted() {

            setTimeout(() => {

            document.body.scrollTop = document.documentElement.scrollTop = 0;

            }, 500);

        }