No really a bug but it feels wrong.
My char ( wood elf ranger ) has 8 profient skills, shadowheart has 2.
I think that companions should have a background too, maybe a unique one that can´t be taken by custom characters.
Companions had a background too before they were captured by the illithids.
It would be really nice if you could show what you are profient with, maybe those skills have an icon or another color.
Now you can see it because they have a different value than the ability modifier, but if you find things that change your skills you cannot tell anymore.