when illuminant fixture is placed above grass the grass turn into dirt like when a full block is placed above grass.

puzzling, doesnt happen for me, i even cranked randomtickspeed to 1k, nothing

Ok! Problem solved! It's been a while since i updated this mod and a bunch of other mods apparently was an issue with the Build 31 1.18.2.

My apologies for not checking that before, i'm new to this github bug reporting thing. 😬

you are fine, looks like this was actually caused by the same thing that caused another problem that i fixed, funny.

apparently grass decides if it can be grass by if the block above it blocks light, which, before the fix, some of the lights did, despite emitting light lol.