cascader 不能用 v-model接收值,需要改为 model-value方式
<el-cascader model-value="selRegion" :options="RegionTreeCascader"
:show-all-levels="true" separator=" - " :props="{checkStrictly: true ,expandTrigger:'hover',value:'id'}" class="list-search"/>
标签：el,element,plus,build,VUE3,cascader,卡顿 From： https://www.cnblogs.com/init-007/p/17402849.html