The bug may have been reported, but I didn't find it.

When you switch an item and use it quickly (such as using it to attack or right-click), the server will still execute the same item as before the switch.

Reproduce：

1、Place one wooden sword with fire aspect and one diamond sword without enchantment in two hotbars

2、Start with the diamond sword

3、Make sure the charging is 100%

4、Switch to the wooden sword and attack immediately

After these, the mob will take fire effect from the wooden sword. But the charging hasn't been reset to 0 before attacking, and the basic damage is still from the diamond sword.