The orientation of the shield in the offhand is reversed.

Next I will show you the bug. Note that a comparison will be made against a resource pack that fixes targeting.

The first two photos without the debug screen are the ones with the fix for this bug.

The other two will be shown without the resource pack and demonstrating the bug.

I also attached some photos of the "shield.animation" codes, one has the fix and the other has the bug. The one in the arrangement has the number "180" in the "wield_third_person" section while the other photo does not have the number "180" and this is the bug