Spears succeed enchantments after crafting with enchanted ones

It's widely known that two equipments with same sort and material can be crafted into one single equipment, and both of their enchantments get lost(except for curses). However, after ＂Mounts Of Mayhem＂update, spear becomes to an exception. When you put two enchanted spear(the picture below takes diamond ones as example)in the crafting areas, you're expected to get an enchanted spear.

●Steps to reproduce:

1.Prepare two enchanted spears.

2.Put them in crafting area.

3.Check out the new spear to confirm if it's enchanted.

●Expected result: The new spear isn’t enchanted.

●Actual result: The new spear succeeds enchantments from the more prioritized one.

Notes:

1. Priority: (up)>(down) , (left) >(right)

2. Enchanted +Normal=Enchanted. This means you can repair your spear without anvil and Mending enchantment.