设置如下css能解决
.mui-scroll-wrapper{
overflow: auto !important;
}
如点击外面遮罩层关闭不了侧栏，需要添加一个<div class="mui-off-canvas-backdrop"></div>在同级就能解决
<!-- 侧栏内容-->
<div class="mui-content mui-scroll-wrapper">
...
</div>
<div class="mui-off-canvas-backdrop"></div>
