TY for the extra tests when you get time! Nothing about the NVIDIA denoiser was changed that I can recall, so it would have to be something else. If you were already using Tent, then it wouldn't be that (the AI denoisers can't work with the High Quality filtering, but it gets silently changed to Tent in IR, and you are prompted for a final render, so there would only be a problem if things were not being changed to Tent, and since you are already using that... it's not that :) ).
If you give it more passes, it should still clean up without artifacts I would expect as then it has more to go on when doing its "AI Stuff". Tricky though it is, the best test would be exactly the same scene in 7 and in 8, which have to be created and saved in 7 since 8 scenes won't load well back into 7. Let us know what you find.
Also, I am doing great thanks :) I hope you are too!