Once the resource pack related to player action changes is activated, the character model in the inventory interface will be damaged in the first-person view, but there will be no issue in the third-person view. This occurs in versions 1.21.6 and 1.21.7. Both the Fresh moves resource pack and the better animations resource pack, once activated, will exhibit the aforementioned issue

Minecraft JAVA 1.21.6-1.21.7（1.21 is normal）
Fabic