when I enter insert mode and then press the Space, then the charater "u" will show up

<img width="517" alt="image" src="https://user-images.githubusercontent.com/8724828/153757653-26bdf05b-0624-4fbd-bc72-4bce9f8c826c.png">
Bug: 
<img width="520" alt="image" src="https://user-images.githubusercontent.com/8724828/153757842-63821735-3412-4f14-8ec8-09c442bb6dd1.png">


my macbook system information,  Xcode version is 13.2.1