Protection is supposed to reduce the general damage of everything but in the latest versions of miencraft bedrock this bug does not reduce the damage of the wither or the poison or instant damage etc being the only one the attack of the magic evoker that defends from the rest no and that is wrong since fighting with witches or wither even the wither boss having IV protection is dangers does not serve you and against the wither boss it does fighting with him is very difficult as portection does not reduce the damage of the wither effect.