New skin does not affect old or future skulls

I finally got a new skin for my extremely old one but it didn't seem to affect the old skull with my old skin.

So I tried giving myself a new skull. It still didn't work.

I believe this can be fixed if I do it on a different world but I would need a structure block just to bring a skull into my own world.

This also affects servers too.

I'm not sure if this was intentional for some reason but I would like this to change please