- [ ] I have searched the [issues](https://github.com/vueComponent/ant-design-vue/issues) of this repository and believe that this is not a duplicate. ### Version 1.7.7 ### Environment chrome last 2 versions ### Reproduction link [](https://codesandbox.io/s/adoring-liskov-yr2yb1?file=/src/App.vue) ### Steps to reproduce 1.select点开下拉,鼠标滚动; 2.下拉列表文字会出现文字从灰色变黑色加粗的情况;(非必然出现,需尝试多次滚动) ### What is expected? 下列列表滚动时,文字颜色不出现变化 ### What is actually happening? 下列列表滚动时,文字颜色会出现变化 <!-- generated by issue-helper. DO NOT REMOVE -->