I was testing the latest Gaea nodes this afternoon. I'm seeing this checkered pattern in all the results in Houdini. The HF in Gaea look clean. This is working off of the “Houdini-erosion” preset that ships with the Labs tools.
I'm still looking to see if I've got something wrong with my set up I don't think that is the issue. Gaea is working fine stand alone and exports are showing up in UE4 with no issues or artifacts. That makes me think this is nearer to the Houdini import side of things.
If others are seeing this it might be proper bug?
EDIT: and FWIW, I am seeing this on 553 and 570 Labs releases, Houdini 18.0.532 and Gaea 18.104.22.168.