@RadiantQueenLove It is always possible to get a defective graphics card, even a new one. It might in fact be the issue here given that you've reinstalled Windows, and therefore the graphics driver, and your dxdiag lists two new crashes of the driver. But before jumping to that conclusion, it's worth trying a slightly older driver. You can find them here:
https://www.nvidia.com/en-us/geforce/drivers/
Try either game-ready driver from May. You'll need to clean-uninstall the current driver again since it's newer.
Please also manually uninstall and reinstall .NET Framework 3.5. Hit Windows key-R, enter appwiz.cpl in the run box, click "Turn Windows features on or off," and .NET 3.5 will be near the top of the list. Click the filled-in box to uninstall, and restart your computer. Repeat the process, clicking the now-empty box to reinstall, and restart.
The other suggestion I have is covered here:
https://devblogs.microsoft.com/dotnet/wondering-why-mscorsvw-exe-has-high-cpu-usage-you-can-speed-it-up/
Most of the errors in your dxdiag are from mscorsvw.exe, hence the suggestion. It's part of the larger .NET Framework system and therefore involved in pretty much anything that requires graphics processing power.
Finally, if you're comfortable working inside the computer, I'd suggest disconnecting and reconnecting the power cables from the graphics card, blowing out the connectors (both sides) with compressed air in between. Do the same with the cables on the power supply side if you have a modular PSU, as in, if you can disconnect the cables at all.
If none of this helps though, I would suggest contacting the retailer for a possible replacement of the GPU, if not the whole system. If you bought the computer from a physical store like Best Buy, bringing it in would be the best option—it's a lot easier to diagnose issues when the machine is right in front of you. Even with an online purchase, the retailer might be willing to facilitate an in-person examination, since that's cheaper than sending back the whole computer, and they may also have other tests for you to run as you're communicating with them.
But don't let repair/warranty service drag it out too long. If the suggestions I've made don't help, and given that reinstalling Windows didn't help, this is precisely the kind of problem that makes warranty coverage necessary.