Vuetify Treeview - Error Loading Children Asynchronously

I am using a client created with Vue Cli which fetches the data in the API made with Laravel 5.

I tried to load child items on a Treeview Vuetify, but it is not working as expected.

Vuetify Treeview

<v-treeview
    v-model="selected"
    :active.sync="active"
    :open.sync="open"
    :items="items"
    :load-children="getChilds"
    open-on-click
/>

Computed "items".

computed: {          
    items() {
        const leafs = [];
        this.items.forEach(item => leafs.push({id: item.id, item.name: name, children:[]}))
        return leafs
    },          
},

Method that returns the children.

getChilds(item) {              
    return new Promise((resolve, reject) => {
        axios.get("/callgetchilds/" + item.id)
            .then(response => {
                item.children.push(...response.data)
                resolve(response)
            })
            .catch(error => {                
                reject(error)
            });
        })
},

But I get the error below:

TypeError: Cannot set property 'vnode' of undefined
    at a.register (VTreeview.js:257)
    at a.created (VTreeviewNode.js:132)
    at nt (vue.runtime.esm.js:1854)
    at Fn (vue.runtime.esm.js:4213)
    at a.e._init (vue.runtime.esm.js:5002)
    at new a (vue.runtime.esm.js:5148)
    at rn (vue.runtime.esm.js:3283)
    at init (vue.runtime.esm.js:3114)
    at p (vue.runtime.esm.js:5972)
    at m (vue.runtime.esm.js:5919)

Someone who has been through this could help me or show me what I am doing wrong.

Thank you

via Chebli Mohamed