• VSCode Version: 1.37.1
• OS Version: ubuntu lts 18.04.3

Steps to Reproduce:

Set "editor.renderWhitespace": "all" for watching easily

1. open a new file
2. press space key
   
3. press space key
   
4. press space key
   
5. press space key
   

we can find the cursor position is incorrect

More info:

1. I has three PCs, their are all ubuntu 18.04.3, but only one is normal.
2. The bug may be not about vscode version. I tried some old version , the bug is still.

Does this issue occur when all extensions are disabled?: Yes