The middle skeleton bone is static?!

I imported some animations from mixamo. On the website the animations are looking very good but in unreal engine the animations are different. If I play a animation on my character then the middle bone is static. It is not moving with the animation and because of this the animations are looking weird. Can someone help me? I dont want that the middle bone is static… I think it is the “pelvis” bone that is static in my skeleton (its the normal skeleton) You know what I mean?