S4S uv island edge splits visible in game

So, I made this hair dryer and everything was going perfectly until I went to test it out in game and the handle, more specifically, the handle rim, looked too bright. In S4S it looks good. In my uv map, the handle is separated from the rest of the structure and that's why studio creates a split there. I thought those splits created by studio on uv islands were supposed to be invisible, but in this case it's affecting how light hits on the object. I had removed doubles at 0.0001 and 0.001 distance, splitted the edges, cleared sharp edges, played with autosmooth values, turned ssao, shine and spec to 0, enabled and disabled vertselfillum, tried different blank specular and bump maps and nothing changed.

I'm wondering if turning off dynamic shadows would help (although I highly doubt it). I'm guessing it has something to do with normals and that my safest solution would probably be unwrapping it again in a way that doesn't separate the handle from the top part but I already created many swatches and i'm trying to avoid that and encountering the same problem in the future.

Here's the blend and package: www.mediafire.com/folder/zyhgbzdogtc6j/hair_dryer

imgur.com/a/rlA3UTv