Router part of PWA opens blank on device (with Vue)

Question

I built 2 PWA based on Vue (with Vue UI templates, with router and PWA already set up) but I get on both the same issue: after I add to Homescreen on device, when I open it from the app icon, the router viez doesn't show up and stays blank until I click on a router link. I don't understand why.

Example of one of them, my portfolio:

URL Link

GitHub Link

Some parts of files here that I think related to the issue:

router.js:

export default new Router({
  mode: 'history',
  base: 'index.html',
  routes: [
    {
      path: '/',
      name: 'home',
      component: Home
    }
  ]
})

firebase.json:

"rewrites": [
  {
    "source": "**",
    "destination": "/index.html"
  }
]

Answer 1

Edit: Checkout @webmint answer below, probably solve problem im better and clean way.

Orginal Post:

I solved my problem adding an alias to start page in routes (in my case "Login")

in manifest.json:

{
...
"start_url": "index.html",
...
}

in router config:

let router = new Router({
...
  routes: [
    {   path: '/index.html',
        component: Login,
        alias: '/'
    },
    {
        path: '/',
        name: 'login',
        component: Login
    },
...

Answer 2

Had same issue. Turns out that solution is quite simple. You have to add/change this in manifest.json

"start_url": "/",
"scope": "/"