• VSCode Version: Tested on VSCode Insiders 1.42.0-insider
• OS Version: Windows 10 Version 1909 (OS Build 18363.592)
• Keyboard: Corsair K95 platinum RGB cherry mx brown

Steps to Reproduce:

1. Map one of your keyboard keys to the f20 key.
2. Go to the keybindings.json.
3. Click on the buttun "Define Keybinding (Ctrl+K Ctrl+K)".
4. Press the button you assigned the f20 key to.
5. It says unknown
   

When I do the same thing but for any key f1-f19 it shows the correct key and works just fine.

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