Basic block shadow is not solid. Inside edge of front where it connects light shines through when the shadow is cast. Uploaded screenshot so example can be seen.
This is just a guess, but most likely the normals on the bevels on the Basic (and maybe other?) Blocks are backward causing light to shine through them. We will need to investigate if this is the actual cause.
Basic block shadow is not solid. Inside edge of front where it connects light shines through when the shadow is cast. Uploaded screenshot so example can be seen.