Hello there!
I also have Razer Kiyo Pro and I encountered also the same issue with the grainy image quality. I also tried different settings and also happens with or without HDR turned on you can play around the sharpness settings and try to reduce to 128]. I think Razer Kiyo Pro needs a very good ambient/environment lighting because when I turned on all the room light including the 2 Elgato key lights (left and right), the grainy image was almost gone (not so noticeable compared with low environment lighting). Btw, I am using a laptop with Intel Core i7 12700H and 3060 laptop GPU.
I have exactly the same issue but I dont remember it being like this before the firmware update but idk whether to roll back or not
I have exactly the same issue. Brand new cam + Razer Book. The image is grainy:(.