The Bug:

The slowness effect is applied to entities when the bane of arthropods enchantment is held in the off hand.

For example, when you melee attack a spider while having an item enchanted with bane of arthropods in your off hand, the slowness effect is applied to the entity you attacked. This doesn't make sense because the off hand item isn't being used.

Steps to Reproduce:

1. Hold a sword enchanted with bane of arthropods in your off hand by using the command provided below.

   /item replace entity @s weapon.offhand with minecraft:netherite_sword[minecraft:enchantments={levels:{'minecraft:bane_of_arthropods':5}}]

2. Summon a spider and attack it using your main hand.

Observed Behavior:

The slowness effect is applied to entities when the bane of arthropods enchantment is held in the off hand.

Expected Behavior:

The slowness effect would only be applied to entities if the weapon used for the attack has the bane of arthropods enchantment.