Are your drivers updated? (I’m sure they are)
Try run an verification check on game files. If that doesn’t work my last suggestion would be a complete clean reinstall of either GFX drivers and/or Game or both. “Clean” meaning you uninstall game/drivers then reboot system before reinstalling game/drivers.
If you have your old graphicscard available you could try installing that and see if the issue is persistent, if not then it could be a fault with your new graphicscard.
If none of this works I’m fresh out of ideas…