Unexpected scrollbar in Affix

[593273894]

Version

3.0.1

Environment

chrome 62.0.3202.94

Reproduction link

https://codepen.io/593273894/pen/wpBvbq

Steps to reproduce

如链接中所示，给affix里的div加上 style={{display:'flex', boxShadow: '0 0 9px rgba(0,0,0,0.2)'}} ，给div里的Menu加上style={{border:'none'}}

What is expected?

无滚动条，正常显示阴影效果

What is actually happening?

向下滚动，Affix右侧出现滚动条，并且box-shadow属性失效