Sorry I didn't get back to you earlier. I didn't see anything obvious in your dxdiag, so I wanted to get a second opinion, from someone who is extremely helpful and will find it completely unacceptable if I say anything else nice about him. He agreed, there's nothing in your dxdiag that would explain the graphics issues.
Are you still applying a high DPI scaling to TS3, as you mentioned earlier? If so, please undo that, at least for now. And of course Game Mode, and Game Bar if it's still a thing, and fullscreen optimization. (I don't have the same Windows build as you, so I can't check if these features are all still present and in what form, but let me know if you need help figuring out how to access the settings.)
Yes, there are ways to revert to a previous build of Windows, but they involve wiping your C drive (again) and chasing down an install medium for that earlier build. (Even the usual download an ISO and install it mechanism only works with a build that's equal to or newer than your current one.) It's certainly doable—for example, I have 1703 on a USB stick, for reasons. But it's a lot of trouble, and not guaranteed to fix the problem, and besides, you'd need to find appropriate drivers too, and download them without allowing Windows to force update.
It's much easier just to fiddle with the Nvidia settings. Control Panel has a number you can try enabling for TS3, maybe a few at a time to see if you notice any difference. Inspector has more, if you want to install it. You can also try the Freestyle filters that come with GeForce Experience, if you're willing to install it. GFE doesn't even crash the game by default anymore, amazingly enough.
The point is, whether this is purely Windows, or some interaction between Windows and the Nvidia driver, there may be some setting that can fix the problem without you having to revert your system and quarantine it from the internet forever.