vue.js – All vuetify selects look like they are selected


Why are all select items blue in this example? It looks like they are already selected.

<v-select
    v-model="obj"
    :items="arrOfObj"
>
    <template slot="selection" slot-scope="data">
        Obj: {{data.item.a}}
    </template>
    <template slot="item" slot-scope="data">
        Obj: {{data.item.a}}
    </template>
</v-select>
let arrOfObj = ({a: 1},{a: 2},{a: 3})

export default {
    data: () => ({
        arrOfObj: arrOfObj,
        obj: {a: 2}
    })
}

I have prepared a codepen for this: Codepen