# Fbx exported file is different to .blend when imported in Unity

I encountered a weird issue today. When I exported my model as fbx and imported it, I noticed the meshes were different to the .blend import. For example there was a hole in my character's head. I went back to check normal and they were all fine. How do I check what is causing this issue and results in different meshes from .blend and .fbx formats?

It is also interesting to note fbx actually keeps all the animations however .blend removed a lot of small animations from my model. Is this normal?