The Spectre Illuminator seems to leave behind shadows from smooth lighting on certain entity blocks.
Known entity blocks include Cable Facades (from Applied Energistics 2) and Framed Slant (from Blockcraftery) - see pictures.
Both entity blocks can be retextured with other block's textures, so this might be what's causing the issue.
Version 1.12.2-4.2.7.4
Project Ozone 3 A New Way Forward modpack
The Spectre Illuminator seems to leave behind shadows from smooth lighting on certain entity blocks. Known entity blocks include Cable Facades (from Applied Energistics 2) and Framed Slant (from Blockcraftery) - see pictures.
Both entity blocks can be retextured with other block's textures, so this might be what's causing the issue.
Version 1.12.2-4.2.7.4 Project Ozone 3 A New Way Forward modpack