Some bones of SK mesh does not play animation

Hi there, I’ve encountered a strange problem with animations. I have a modular character with separate skeletal meshes, all sharing the same skeleton. But when I try to assemble the full character I found out that some meshes are unable to play animation on all of their bones. For example in attached screenshot both head and hair models are playing the same idle animation, but you can see that some head bones remain still. This problem only appears in skeletal mesh component of the actor, it doesn’t show itself when in skeleton editor. Does anyone knows why is this happening?

Found the problem. In LOD 1 some bones are suppressed, and for some reason, probably an engine bug, meshes were ignoring LOD rules, always staying in reduced LOD 1.