Vuetify `v-data-table-virtual` not selecting all items

I want to use a v-data-table-virtual from Vuetify to show API scopes. The problem is that I have 643 scopes but when selecting all rows it only selects 611 scopes.

Here are the relevant parts of my Vue component:

<template>
    <v-data-table-virtual
        v-model="selectedScopes"
        :headers="headers"
        :items="allScopes"
        :height="600"
        fixed-header
        show-select
        item-value="scope"
    />
</template>

<script setup>
import { onMounted, ref } from "vue";

const app = useApp();
const api = useApi();

const allScopes = ref([]);
const selectedScopes = ref([]);

const headers = ref([
    { title: tc("Scope"), value: "scope" },
    { title: tc("Method"), value: "method", width: "150px" },
    { title: tc("Scope group"), value: "scope_group", width: "150px" }
]);

onMounted(async () => {
    await getScopes();
});

const getScopes = async () => {
    try {
        const response = await api.get("/core/scopes");

        // respones.data.length = 643

        allScopes.value = response.data;
    } catch (error) {
        app.setError(error);
    }
};
</script>

Why when I select all scopes it only selects 611? Why this specific number?

Most likely some items contain the same value in scope. Check that there aren't any duplicates (same scope different method?) and consider setting a different property in item-value, which is used to check if an item is already selected.

Vuetify selects only one item for every distinct value found under the item-value property.