Minecraft 1.20.1, Forge 47.3.0

Tested with FPM 2.4.3, MCA 7.5.18, and Architectury 9.2.14 (MCA dependency).

This happens when either vanilla hands mode is enabled or even when the first person model is completely disabled using f6.

With FPM but model disabled to show vanilla hand (shows non-MCA regular player skinned hand):

Without FPM installed (shows MCA player skinned hand as expected):

It doesn't break anything, but it's kind of immersion breaking, especially in vanilla hands mode where the arms don't match the rest of the skin.