This has been a bug for as long as I can remember, so basically what happens here is that items that are in your hand are slightly rotated to the left (or right, depends on if it’s on the offhand). Blocks are not affected by this.

I left some attachments with text showing which version is which for you to easily notice the difference.

Steps to reproduce:

1. Hold any items in either hands (cant be a block)
2. Go in 3rd person front
3. Look closely at the item

Expected Results:

The item should be facing straight forward.

Observed Results:

The item is slightly rotated.