You need to disable "Real-time protection", like this :
- Run Settings > Privacy & security > Windows Security
- Click "Virus & threat protection"
- In the Virus & threat protection window, under "Virus & threat protection settings" click "Manage settings"
- In the Virus & threat protection settings window, set "Real-time protection" and "Dev Drive protection" to Off.
The effect is immediate, no reboot required. You should undo this when you're not playing the game.