scrollBehavior does not run on load

[Calvin-LL]

Version

3.1.6

Reproduction link

https://codesandbox.io/s/vue-routing-example-pk4q2

Steps to reproduce

Load page

What is expected?

scrollBehavior always return { x: 0, y: 200 } so the scroll position should always be 200 pixels from the top

What is actually happening?

scrollBehavior always return { x: 0, y: 200 } but scroll position y is always 0 when first loaded

[Calvin-LL]

relevant issues: nuxt/nuxt#4024
similar problem in forum post: https://forum.vuejs.org/t/scroll-behaviour-doesnt-work-on-initial-page-load/69210/2
similar problem in stackoverflow post: https://stackoverflow.com/questions/45201014/how-to-handle-anchors-bookmarks-with-vue-router/45206192#45206192