Quick answer: Unreal Niagara particles attached to a skeletal mesh bone jittering relative to the bone? Niagara tick group != animation tick group - set Niagara tick to Post Update Work.
Sword trail particles lag behind the sword by one frame.
Post Update Work tick
On the Niagara component, Tick Group = Post Update Work. Animation has finished; bone positions are final.
Or sample on pre-physics
If your animation finishes pre-physics, sample bones there. Earlier tick; less risk of frame lag.
Verify with stat Anim
Compare anim tick group to Niagara tick group. They must agree on order; mismatch = visible lag.
“Tick order matters for sample-from-other-system effects.”
Standardize on Post Update Work for VFX that read animation. Document; new emitters inherit the convention.