S3220DGF, A04, G-Sync black screen flicker FIX

Hello,

After I have read a lot of things to try to set my 2 Dell S3220DGF revision A04, here is the solution which is working to remove all issues with one or two screens :

Do a clean reinstallation of the NVIDIA driver when you have the screen plug to your computer. It has resolved color issue for me. If it still doesn't work after that, you can go to device manager and uninstalled your Graphic card driver from here. 

Also you need a VESA certified DP cable 1.4. This is really important. On laptop USB-C to DP (Maxonar, Club 3D) seems to be more stable than Mini DP to DP (Cablematters, Club 3D). But if they are certified, both cable type will work well (I do not recommend cable matters. Both cables seem less stable than other certified brand). Once connected you'll need to do those settings

In Nvidia control panel use these settings :
- Go in change resolution tab
- Refresh rate at 164Hz
- Use NVIDIA color settings instead of default settings
- Highest (32-bit)
- 10 bpc
- RGB
- Full

In your screen OSD :
- Go in Game settings
- Be sure Freesync is ON
- Response time is Super Fast
- GO in Display settings
- Be sure input color format is on RGB and not YPbPr.
- Smart HDR at Desktop

Those settings are working at 164Hz, 10bits and HDR very well without any brightness variation and screen blacking/flickering. No need to use CRU.

If after some time you are facing some brightness variation just do this solution :
- Go in change resolution tab
- Open Nvidia control panel
- change output dynamic range to limited and click apply
- change back output dynamic range to full and click apply

This should resolve the issue until next sleep mode.

I hope this will help people that still have issues with the S3220DGF. I can't say if this is working for old revision as my 2 screens are Rev 04.