Is there an existing issue for this?

• I have searched the existing issues
  To pick up a draggable item, press the space bar. While dragging, use the arrow keys to move the item. Press space again to drop the item in its new position, or press escape to cancel.

Can the issue be reproduced with the default theme (daylight/midnight)?

• I was able to reproduce the issue with the default theme
  To pick up a draggable item, press the space bar. While dragging, use the arrow keys to move the item. Press space again to drop the item in its new position, or press escape to cancel.

Could the issue be due to extensions?

• I've ruled out the possibility that the extension is causing the problem.
  To pick up a draggable item, press the space bar. While dragging, use the arrow keys to move the item. Press space again to drop the item in its new position, or press escape to cancel.

Describe the problem

在提及中，键盘会被错误的渲染高亮。如下图所示：

经过测试，这个bug在2.8.5以前均不存在，这应该就是这个版本引入的bug。

刚刚测试了一下，2.8.6的后三个dev版本均不存在这个问题。

且应该也不是文档的问题，将2.8.6的帮助文档导出sy并导入到新的笔记本中，在2.8.6 dev4中不会见到这个问题，改成2.8.6正式版又会出现。

Expected result

能够正确的渲染。

Screenshot or screen recording presentation

No response

Version environment

- Version: 2.8.6
- Operating System: win10 ubuntu20 
- Browser (if used):no

Log file

无需日志

More information

No response