nuxt@2.15.4 $router.back not work as expected

[Jogiter]

Versions

• nuxt: V2.15.4
• node: v14.15.1

Reproduction

https://codesandbox.io/s/nuxt2154-routerback-error-7s1p8

online demo

module.export.default = {
 // Disable server-side rendering: https://go.nuxtjs.dev/ssr-mode
  ssr: false,

  // Target: https://go.nuxtjs.dev/config-target
  target: "static",

  router: {
    mode: "hash"
  },

 // default ...
}

Steps to reproduce

1. navigate from home to about
2. refresh about 3 times
3. click a button to call $router.back(), the page is still about
4. after i clicked the back button 4 times, it navigate to home

What is Expected?

after the back-button once, it`ll back to home

[Jogiter]

the same config with nuxt@2.15.3 Reproduction

demo

$router.back() work as expected.

[kozo002]

The same bug happens in https://nuxtjs.org/

[danielroe]

Closing in favour of #9111.