a story of skeleton in unreal, during 2 weeks I tried to fix it, asked everywhere I could, checked google, youtube, unreal forum, no one knew.
I don't remember exactly, but apparently a skeletal mesh was missing bones or something like it. So i've deleted and reimport all DAZ skeletons and also desinstalled daz to unreal, I did the same for the meta humans, I opened the project in a blank project I had the same issue? 2 weeks of searching and nothing
ah bones in meshes isn't that hard of a fix.
try this > Skeletal Editor Usage Guide | Epic Developer Community (epicgames.com)