Alright, I'm done searching. Turns out this isn't the most common fault this card has (mostly overheating and artifacting) so I didn't find anything of value to you.
I'm not certain but if you are able to turn off shadows (if that even is possible) perhaps it'd work? If that doesn't work, turn off some other settings, and if you see the problem disappear then you know what the problem was
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By the way, you should also talk to nvidia, and the store you bought the card from. They might give some pointers. If not, it isn't the biggest problem I've ever seen.
/Breaker