Hello, some issues could actually be because Unreal Engine now (not sure how long) supports 8 vertex per bone skinning.
For example in 3dsmax, if you don’t specify 4 bones in the skin modifier it will default to 20 which in turn will activate 8 vertex per bone skinning in Unreal Engine.
This can be fixed by limiting the skinning to 4 bones.
Also we are working on an update which will include support for 8 bones (switching between 4 and 8 automatically same way as UE). Still, 4 bone skinning will be faster so, it’s a good idea to go that way with more expensive feature like fur.
The update for PRO version will also contain support for animated morphs.