Enchantments on the item in your main hand influence the spear's charge attack when held in the off hand

I use the spear in my left hand with my fire aspect sword is in my right hand. I charge at a chicken with the spear, it dies and gives me cooked chicken even though my spear has no enchantment.

How to reproduce:

1. Give yourself any spear and a sword enchanted with any level of Fire Aspect.

2. Put the spear in your off hand.

3. Summon a chicken.

4. Move away from the chicken.

5. While holding the sword in your main hand and the spear in your off hand, charge at the chicken and kill it.
   -> ❌ Cooked chicken is dropped.

Expected result:

Enchantments on the item in your main hand do not affect the charge attack of a spear held in the off hand.

Observed result:

Enchantments on the item in your main hand affect the charge attack of a spear held in the off hand.