Skeletal mesh - can't apply textured materials to certain elements

I have imported this skeletal mesh as an FBX from Clo3d into Unreal and realised that when I apply materials to the elements, some of them do not get the texture and it only has a smooth colored surface without any details (see img for reference - round link has it, the one next to it doesn’t).
In clo3D I imported these accessories as trims from blender - the round one works because I have done it myself in blender but the link chains (the ones with the smooth surface) were given to me by my client as objs. I have tried figuring out what is wrong with them but I cannot find a solution. Any ideas? Thank you!