Item disappears when imported into a different LOD

Hello! I hope someone can help me with this. I tried to edit a child necklace is blender and add a skull to it, so my character could cosplay Gaz Membrane from Invader Zim. Everything went smoothly until I got to the import process (I used Import 3D mesh, I double checked). I imported it into LOD 0 with no issue, but LOD 1 and onwards made it turn invisible. I haven't put it into my game as of yet, but I'm wondering what I can do to remedy this as of now. Thank you for reading! I will give as much information as needed to help resolve this issue. :D