• VSCode Version: tested 1.35.1, 1.37, 1.38.1, probably also exists in earlier versions.
• OS Version: Win10 and VM Win7 and VM Debian 10.

Steps to Reproduce:

1. Open Settings.json
2. Click any edit menu which is on the bottom of the screen.
3. If you release your mouse, the entry will be selected immediately. Because the menu doesn't show up in the right place.

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