element中el-select下拉框位置错乱问题

<el-select
          class="item-value"
          :popper-append-to-body="false"
          :disabled="busTypeDisabled"
          v-model="formData.busType"
          @change="busTypeChange"
          placeholder="事务类型">
          <el-option
            v-for="item in busTypes"
            :key="item.value"
            :label="item.label"
            :value="item.value"
          />
        </el-select>