Alot of us has been requesting SMAA for unreal engine, I don’t know if certain lighting causes TAA ghosting effect to become more apparent (Lumen does contribute to it as well but this has been happening in UE4 as well) but some materials definitely make it worse.
This won’t help with ghosting but will make your scene look a bit sharp. I found those sometime ago during my own Googling into this.
r.Tonemapper.Sharpen 0.65
r.TemporalAACurrentFrameWeight 0.2
r.TemporalAASamples 4