If you have been using Slack/Chrome and VSCode for the past few weeks, you might have been experiencing the issue. Basically, when VSCode is minimized and you are scrolling in Chrome with the mouse wheel, the input is “stacked” and applied when VSCode is brought back to the forefront. When you click inside the application window, the input is immediately processed.
This causes the cursor to jump around and is a pretty big annoyance.
Ubuntu 19.10 fixes the issue but I’ve reinstalled a Debian 9.9 which still faces the issue.
You can track the following Github issue for more details : https://github.com/Microsoft/vscode/issues/28795