[Vuejs]-Having vuefire+firebase binding collections error

As firebase takes some time to fetch data, the DOM is getting loaded first.

you may try doing like this.

firebase: {
  citiesFromdb: db.ref('cities'),
  countriesFromdb: db.ref('countries'),
}
computed: {
    cities() {
        return this.citiesFromdb;
    },
    countries(){
      return this.countriesFromdb;
    }
}