Ragdoll bones missing on imported physics asset

I made a rigged mesh of a hanged man in Blender which works fine in there, wanna use it as a ragdoll model in UE5, but for some reason the ragdoll bones are missing, apart from one big one:



No idea why, I made a similar one with a Mixamo rig, where the ragdoll works perfectly.
Haven’t found any clues with googling, any help is appreciated!