Steps to reproduce :

 - put a Poison II in a brewing stand

 - add a fermented spider eye and blaze powder

 - The brewing stand gives a Harming I potion

Excpected results :

the brewing stand should give a harming II potion (according to wiki)

The issue is in the file :

behavior_packs\vanilla\recipes\brew_strong_poison_fermented_spider_eye.json

line 12 :

"output": "minecraft:potion_type:harming"

should be :

"output": "minecraft:potion_type:strong_harming"