so I checked the bones and compared them and the main things that are missing is root bone which should be at (0.0.0) spine_04 and spine_05. If you could also add IK bones to the anima for the FBX for unreal engine, i think that could really help with compatibility issue. the naming issue could also be fixed but if the bones are added could help.
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The Armature is the root of the model, Anima doesn't have a spine_04 or spine_05 and to add them would involve re-rigging, I should be able to fix the naming issues, I didn't make the rig with IK in mind, as you can usually add that in the game engine. I do not have vmd files for the the animations.