I'am install ars nouveau(last and prev) in mohist (last and prev), server online-mode=false, install skinsrestorer.
Accessories not work
i'am delete skinsrestorer
Accessories work...
in online-mode=true Accesiries work
\o/
Another plugins for fix skin in unofficial server give the same effect

In 1.18.1 everything works fine

(online-mode=true)

Hello,
Mohist is not supported for this mod.
If you are referring to accessories as that tab, that is the mod Curios, not Ars Nouveau. I don't expect Curious to support Mohist either though.