Skin rendering bugs

[Jerozgen]

Please confirm the following.

• I checked the existing issues for duplicate problems
• I have tried resolving the issue using the support portal
• I have ensured my Modrinth App installation is up to date

What version of the Modrinth App are you using?

0.17.3

What operating systems are you seeing the problem on?

Windows

Describe the bug

1. Ears skin elements shift the model pivot point:

   pivot_shift.mp4

2. The shadow circle beneath the player is incorrectly rendered on top of the inner skin layer:
   

3. The outer skin layer is rendered single-sided:
   

Steps to reproduce

No response

Expected behavior

1. The model should rotate around its main central axis
2. The shadow should render behind the entire model
3. The outer skin layer should be rendered double-sided as it is in Minecraft:
   

Additional context

No response