I noticed that when I use the blur brush set to affect just the detail layer, then adjust the detail level (to say .46 or something), then start brushing, I seem to reveal a tile pattern in the image:
How big is your image?
5672 x 3192
I think this is the same issue that I had before, they said its a bug:
Ah, indeed, it’s the same bug.
For now, you can use the Detail Separation Using Nodes workflow and as long as view and edit the Paint nodes while painting, you will not see the tiling artifacts.