Why does my Dell laptop monitor give this weird color banding?

Question

I've noticed some very obvious color banding on the screen of my Dell Precision 7750 laptop while watching video (same in every video program; VLC, built-in Windows video player, etc.) Not only does this not happen for the same video on other computers, but also when I plug in a second monitor to the laptop and play the video on there, it looks find on the second monitor. So it seems like it's something to do with the color profile on the main laptop monitor. Here's what the banding looks like:

I took a screenshot and pasted it in GIMP to check the actual pixel values. Zooming in on a particular banding edge as an example, there was a very noticeable difference between pixels of colour #040404 and #050505:

I then made a #060606 pixel and as you can see, it looks almost identical to the #050505, so something is causing #040404 and #050505 to look quite different when they should be almost indistinguishable, but this doesn't apply to most small changes in pixel colour:

What could be causing this effect on the laptop screen? A screwed up colour profile? The system has onboard Intel graphics, but is using the installed nVidia Quadro RTX 3000 graphics card.

Answer 1

This was just going to be a comment but it go to long...

Is this being streamed? If the connection speed is to low then the a lower quality video will be streamed with most services. Also, check the "video" settings on the NVidia card settings page. There should be an entire tab on video settings, make sure the best quality and true color settings are selected. Also make sure the "use hardware decoding" options are turned on. It is also possible to "override" the software settings. Lastly check your windows settings just to make sure full color is enabled and that the best video quality settings are turned on. Most of these settings can be accessed just by right clicking on the desktop and choosing "Nvidia control panel", and "display settings"...usually.

Under the windows "video playback" page there is a video which can be played, set that to full screen to see if the banding exists on it, if not then it is mostly likely the source video quality/download speed issue. If it has bands then it is likely a setting in windows or the video driver.