element-ui 日期选择器报错 Prop being mutated: "placement"

报错信息

解决方法，添加placement="bottom-start"

<el-date-picker
  v-model="queryParams.startTime"
  type="date"
  placeholder="开始时间"
  value-format="yyyy-MM-dd HH:mm:ss"
  placement="bottom-start">
</el-date-picker>