Minecraft - 1.20.1
Forge - 47.4.0
KubeJS - 2001.6.5-build.16
KubeJSTFC - 1.3.2
TFC - 1.3.2.18

When creating a new TFC dirt block the grass block renders with running water down the side that makes it darker than adjacent blocks. This issue persists even when setting the renderType for the grass block to cutout or cutout-mipped. There is no issue with rendering the other blocks (farmland, path, dirt, rooted dirt) except as present in vanilla blocks as both vanilla path and farmland blocks have that running water render issue.

Thanks for the report, this will be fixed in 1.3.3