Hello. Great mod you got there. Im a long term user of your mod. Recently i tested it with cubic chunks and at negative block y coordinates, lamps, pipes and several other items are becoming invisible and untargetable after placing (also lamps in addition dont emit light, not only theyre not invisible and untargetable).
Forge 2768

https://github.com/OpenCubicChunks/CubicChunks

I will report further issues when i find them.

Closing this because Cubic Chunks doesn't seem to be ported to 1.15+