This has been a bug before Future is Bright was a project. Shadows from dynamic lighting are casted based on the mesh’s collision model, not the actual graphic model. The shadows can be fixed by setting the mesh’s collision fidelity to “Box” (“Hull” also works to some extent).
This is a really annoying bug, and I hope ROBLOX gets around to fixing it.
Sunlight doesn’t use the Voxel grid for direct sunlight in ShadowMap, only for indirect ambient sky lighting, so this would only apply to artificial lights or sunlight in Voxel lighting.
Sorry for not coming to you earlier. These shadows should not be present. Scaling it up makes it worse. There is nothing wrong with the mesh itself, and this should definitely be treated as a bug.