I found something weird and thought I'd post it here. So if anybody else find has something similar he or she knows whats up.
I was doing some testing with the denoiser Noice and found some weird diagonal lines in the denoised result. After some looking around I found the depth pass, which is used by the denoiser, to be the culprit.
It turns out if you're working on a big scale (client file) the depth pass can have a weird result.
This gets used in the denoiser and results in a weird effect.
So the fix is simple. Scale the scene down and it's all fixed
depth pass graded to see the effect
noisy render
denoised render with the artifact