smoothing groups work on scene, but not on build

so, I've been having this problem with my 3D mesh, where only the face glitches the smoothing group, but the funny part is that it only glitches when I build it, in the scene is just fine, and the rest of the body works smoothly, even beeing the same fbx. can someone help me? I'll put some images showing the problem. I've imported the fbx from 3Ds Max, where the smoothing groups are just fine as well. I'm building with void AR for android. Can someone help me please?