I’ve uploaded three files that produce artifacts (even worse). The issue appears also with TIFF files (I processed NEFs in my Zoner Photo Studio, saved them as TIFs), loaded to Photo AI, but failed.
I tried Topaz DeNoise (recent version) and ran into same kind a problem.
Will test the Strong model with lower strength.
with kind regards
P.S: I got disappointed with lack of answers from your side. Please consider to answer sooner (event with no solution) - that prevents your visibility as inattentive.