Bug: NPCs loosing their skin

### In which plugin has the error occurred?

FancyNpcs

### What happened?

Sometimes after rejoining the NPCs just loose their skin. If i reload the plugin or "fix" the specific NPC the Skins reappear

### In which software has the error occurred?

Paper

### Plugin version

2.11.0 (Git: 3ee8da3)

### Server version

1.21.11

### Relevant log output

```shell
No log output
```

No source file, test, or entry point is identified. First reproduce the issue on Paper 1.21.11 with FancyNpcs 2.11.0 by rejoining, then compare the NPC skin state with the result after reloading the plugin or fixing the NPC. Done means skins remain visible after rejoining without either workaround.

Written by the indexing model from the issue text.