Seems pretty self-explanatory.

Tested with and without shaders, all non-full blocks (stairs, slabs, walls) of Nether Brass glow, but not full blocks. Not sure what is intended behavior here to be honest. If this is intended, unifying the behavior between full blocks and partial blocks would be nice.

definetly not intended, fix released soon along with the other sunmetal issue, thx for reporting <3