Shading issues with mesh merged skeletal mesh [5-0.]

Hello!

I’m working on a modular character and initially following the Mesh Merge method described in the wiki, copy pasting the code from there.

The merging seems to go fine except that the shading seems to be off. I’ve provided a screenshot with the mesh imported as a full mesh, meshes pre- and post merge. I’ve been fumbling a bit in the dark here as to where to begin to troubleshoot, but so far found nothing.

Any ideas on where to even begin?

Shading

Tried this out in 4.26.1 with the same assets and the issue is not replicated there.