Extra border in fullscreen mode

[usernamehw]

Issue Type: Bug

1. Go fullscreen
2. Put cursor on the rightmost part of the screen
3. There's a border on the right part of the window that can't be dragged to scroll

VS Code version: Code - Insiders 1.47.0-insider (7e4cc2c, 2020-06-12T06:03:53.183Z)
OS version: Windows_NT x64 6.2.9200

[usernamehw]

Actually a zoom issue.