You have a TN panel. There will be some bit of banding present, and it's not even capable of 10-bit, not sure why you're enabling it?
You know there is banding from gamma adjust when using Nvidia GPU right ?
AMD have temporal dithering enable by default for decade and don't suffer from the same fate.
Also Nvidia + Linux = no banding due to 11 bit internal LUT plus there are many dithering methods to deal with , while Nvidia + Windows = banding from 8 bit internal LUT with zero dithering to choose.
This is not limited to TN panel. Try gamma adjust on IPS monitor like PG279Q and you will see banding.
But currently I can deal with it by dithering registries hack. It is already present in Linux and it can take less than 30 minutes for Nvidia engineers to implement this to Nvidia control panel in Windows but they don't do it anyways for some stupid reason.
I make a video to test about performance loss from enable dithering. There is zero penalty , it doesn't turn 1080 Ti to 1080 so I don't understand why they ignore this request since 2015.
Quadro also have access to dithering in Windows via NVWMI. This again proof that dithering is already present in Windows.
So in the end
if you calibrate your monitor.
1.Any Nvidia cards + Linux = no banding.
2.Nvidia + Windows = various results.
2.1 Quadro + Windows = no banding.
2.2 Geforce + Windows = banding
2.3 Geforce + Windows + dithering registries hack (NOT officially support) = various results.
2.3.1 Geforce + dithering registries hack + Windows 7 / 8 / 8.1 / 10 1507-1607 = no banding.
2.3.2 Geforce + dithering registries hack + Windows 10 1703-1803 = no banding with some minor issues.
2.3.3 Geforce + dithering registries hack + Windows 10 1809 = no banding with some major issues.
2.3.4 Geforce + dithering registries hack + Windows 10 1903 = constant banding everywhere because it doesn't work anymore.
Since dithering registries hack is NOT officially support by Nvidia any problems that happen with Windows 10 1703 and later cannot be solve. We only have some workaround methods to deal with it.