shield going on inventory slot after equipping on offhand

[yowaht]

Describe the bug I equipped my shield on my offhand, but randomly, it goes into my inv slot, this bug doesn't happen on when i'm wearing regular armor, but if I wear this armor, that happens

To Reproduce Steps to reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

Expected behavior I thought it's gonna be fine

Screenshots If applicable, add screenshots to help explain your problem.

Technical Information (please complete the following information): ! Please provide the actual version, not just 'latest'.

• Minecraft-version: 1.21.10
• ModLoader-version: idk
• Mod-version: idk

Additional context Add any other context about the problem here.