Using Unity asset models in UE4

Im trying to import synty models by first importing them on blender. I only have bought unity assets and don’t know other way how i could use them on unreal than first importing to blender and export fbx.

After that i import them to UE4 and Models look good on unreal but when i use mixamo animation on them, model changes to this wierd looking guy. I have imported my own character to mixamo and everything looks good there.

Does anyone have exprience what causes this stickfigure guy appear, or how to corretly get unity asset models to work in UE4?