Screen flickers black/white after launching

ElJEfeman77  I've split your post into its own thread because the other thread, despite its title, is mostly about a specific problem on certain laptops that don't have much in common with your system.  Your dxdiag shows that your Nvidia graphics driver is very old, so please update it.  Go here:

https://www.nvidia.com/en-us/drivers/

Choose Nvidia RTX/Quadro, Quadro Series, Quadro K620, Windows 10, and download the Release 550 driver.  Run it as an admin: right-click the download and select "Run as administrator."  Restart your computer afterwards.

Separately, if your monitor supports DisplayPort or DVI, please find a corresponding cable and plug the monitor directly into the graphics card, not the motherboard as you've currently done.  A new-enough monitor should support DP at least, but an older one might not, in which case you'd need an adapter.  But you do want the graphics card running the monitor for best performance.