[Bug Report] cascader组件修改v-model值不触发lazyLoad

[yutons]

Element UI version

2.15.14

OS/Browsers version

chrome

Vue version

2.7.16

code

    <el-input v-model="input" placeholder="请输入内容" @change="change"></el-input>
    <el-cascader v-model="value" :props="props"></el-cascader>

<script>
  let id = 0;
export default {
  data() {
    return {
     input: '',
        value: [],
        props: {
          lazy: true,
          lazyLoad(node, resolve) {
            const {
              level
            } = node;
            setTimeout(() => {
              const nodes = Array.from({
                  length: level + 1
                })
                .map(item => ({
                  value: ++id,
                  label: `选项${id}`,
                  leaf: level >= 2
                }));
              // 通过调用resolve将子节点数据返回，通知组件数据加载完成
              resolve(nodes);
            }, 1000);
          }
        },
    }
  },
methods: {
      change(value) {
        console.log(value);
        let _this = this;
        setTimeout(function(){

        },500)
        _this.value = [ 1, 2, 4 ]
      }
    },
}
</script>

问题现象