Hi! I managed to sort out my GPU performances with a trick used by NVIDIA users: The problem comes from Microsoft Automatic Updates where you can find settings in the MPO preventing the GPU to boost, and if I tried to OC it I ended up with a crash with mention "Driver Time Out".
Microsoft also forces their drivers to AMD users AMD alert
The fix comes from an app sorting out the issues of flicker or stutter on NVIDIA GPUs after updating to NVIDIA Game Ready Driver 461.09 you can find the link to its download here hmpo_restore.reg
As a result my GPU can run at maximum frequencies without any issues even higher if you O.C it, My Settings.
I have very good air cooling and my GPU runs fast and cool, but I am certain that this is not the only thing that holds its performances...