Smoothing groups/Lighting inconsistency

Hello, I am building a functional pinball machine gamemode/map for GMod - all is going swimmingly, but I have had an issue with the lighting for quite some time that is really starting to bug me. I have applied smoothing groups, aligned and uniformly scaled textures, remade the brushes, tried many lightmap qualities (this screenshot is at 16), I am not getting any errors in the compile log, and have func_detailed correctly. But, for some reason that still eludes me, these two triangular brushes still have incorrect lighting. I know this is far from the end of the world - but it is a highly noticeable artifact in a highly noticable location that subtracts from the feeling of quality.

My question is - does anyone know why this is, or have any suggestions as to what to try next?

Many thanks, and the kindest of regards.
Sneaky

Image:

Nevermind - I fixed it by changing the geometry so I could have both triangles part of the same func_detail as the rest. Feel free to delete/close topic.