Cod and Salmon dropping cooked variations instead of raw when killed without fire aspect enchantment

Cod and Salmon dropping cooked variations instead of raw when killed with diamond sword (knockback 2, unbreaking 3, looting 3. sweeping edge 3, smite 5, mending) and diamond ax (unbreaking 3, efficiency 4)

What I expected to happen was...:
fish drop raw versions of self

What actually happened was...:
fish drop cooked versions of self

Steps to Reproduce:
1. swim in the water
2. kill fish with sword
3. collect dropped fish (cooked) 

4 repeat with ax