I haven't played Sins in a few weeks, so a few things could have changed.
First, the Sins game could have been updated.
Second, the Nvidia driver was recently updated.
Third, there was a recent Windows 10 1809 update.
When I tried to play Sins tonight it would load just fine. And I could use the keyboard to switch controls and Enter to apply them. But whenever I moved the mouse the monitor went blank and the monitor lights indicated no signal. Then it would restart the video link and the monitor would come back in a few seconds.
It was not a driver crash because Youtube videos on the second monitor continued to play.
Other games worked fine.
Sins seemed to work in windowed mode.
The monitor is a 3840x2160 G-Sync on an Nvidia 1080 Ti.
And ideas or fixes for this?