I'm using the latest version of CW Control (ScreenConnect) as of the time of this post, and have found that my one of my graphics adapters is not compatible with the ScreenConnect "blank host screen" feature. Basically the remote window & host will constantly flash black and never "stay" black. It flashes indefinitely.
I worked with tech support to identify the issue and they advised me to post this as a feature request.
Device: Startech USB2DVIE2
Driver Name: Trigger II External Graphics
Driver Version: 1.4.1802.810
Customer support service by UserEcho