After pressing the Use Item/Place Block key (right-click by default), the horse armor/wolf armor that is located in the off-hand swaps with the item with the main hand. Pressing the Use Item/Place Block key again does not swap the items back.

Steps to Reproduce

1. Put horse armor/wolf armor in your off-hand
2. Press the Use Item/Place Block key with any selected hotbar slot

Observed Behaviour

The horse armor/wolf armor that is located in the off-hand swaps with the item with the main hand.

Expected Behaviour

Nothing happens when pressing the Use Item/Place Block key with horse armor/wolf armor in the off-hand.