Also, when you retargeted, in the skeleton, did you by any chance change the preview mesh to this male metahuman size skeleton or did you leave it as default? The default does not seem to have any of the finger and toe bones.
I’ve noticed Retargeting work best if before retargeting you do change two things:
i) the preview mesh
ii) the pose you use for the retargeting; metahuman come with a variety of these to cover all the various combinations (same as for the preview mesh: female vs male, normal slim overweight, normal tall short)
If you’re retargeting UE4 animations to UE5 metahumans using IK Retargeters found in Lyra, make sure to set all “Metacarpals” in the Chain Mapping tab to “None”. That will prevent finger distortion when converting old UE4 anims.