External Display Goes Black When Drawing

Microsoft reported a bug on Windows 10 version 2004 for applications using drawing on duplicated displays

FlatFrog Board for Rooms users who are using Windows 10 version 2004 may see this issue if they are using duplicated displays. To workaround this issue, we recommend you try one of the following:

1. Change your display setup to Extend by pressing the "Win+P" on your keyboard 
2. Downgrade your computer to Windows 10 version 1909
   Or
3.  Download and install the October 1, 2020—KB4577063 (OS Build 19041.546) update (Microsoft recommended solution).