The second layer does not appear on the NPCs

[Vulqa]

Describe the bug
When I create an npc using the API, the npc skin does not appear with the second layer
(I compiled the plugin from the source code of github)

NPCLib JAR name
npclib-plugin-2.12.1-SNAPSHOT.jar

Server version
This server is running Paper version git-Paper-562 (MC: 1.16.5) (Implementing API version 1.16.5-R0.1-SNAPSHOT)
You are 13 version(s) behind
Previous version: git-Paper-443 (MC: 1.16.5)

To Reproduce
Just create a NPC with a second layer

[JitseB]

Version 2.12.1 is a pre-release and is not meant for production servers. Have you tried version 2.11.1?

[Mooselk]

I think this might actually be my fault, I created a pull request fixing this for most versions only to find out it didn’t work on 1.16 and maybe 1.15. I can’t remember if I created a pr to correct my mistake.

[Syncx1]

Problem is present on 2.11.1