Vuetify v-treeview不打开嵌套节点

<template>
  <v-treeview :items="treeData">
    <template v-slot:label="{ item }">
      <v-icon @click="toggleNode(item)">{{ item.open ? 'mdi-chevron-down' : 'mdi-chevron-right' }}</v-icon>
      {{ item.name }}
    </template>
    <template v-slot:item-children="{ item }">
      <v-treeview :items="item.children" v-if="item.open"></v-treeview>
    </template>
  </v-treeview>
</template>

<script>
export default {
  data() {
    return {
      treeData: [
        {
          name: '节点1',
          open: false,
          children: [
            {
              name: '子节点1',
              open: false,
              children: [
                {
                  name: '子节点1-1',
                  open: false,
                  children: []
                }
              ]
            }
          ]
        },
        {
          name: '节点2',
          open: false,
          children: []
        }
      ]
    };
  },
  methods: {
    toggleNode(node) {
      node.open = !node.open;
    }
  }
};
</script>