Why does my mesh deform like this?

I took the trooper skeletal mesh from the Matinee Project to test cloth simulation in UE 5.3. Because the mesh has a lot of bones to actually control the skirt of the character, I exported the mesh into maya, deleted all the skirt joints and skinned the skirt 100% to the pelvis joint of the skeleton. Then I reimported the trooper to Unreal, but for some reason the skin deformation behaves differently in Unreal then in Maya (and yes, my skin deformation method is set to linear in maya).

But the actual strange thing is, that Unreal displays the correct skin values, while it still deforms the mesh differently. Please see the Images attached. In the first image you can see the skin weights of my thigh_l joint. In the second image you see the deformation that happens when I rotate the thigh_l joint.


As you can see, according to the skin weights, the skirt of the character shouldn’t deform at all when I move my thigh_l joint. Unfortunately it does tho.

Any ideas?