1.19.2
The extra magical damage bonus given by the warlock hat can be exploited by unequipping then reequipping it over and over, and it'll keep stacking. This stacked damage bonus is, however, lost on death.

Edit: the same may possibly be true for the warlock chestpiece's damage reduction, but it's unconfirmed.

I know the cause, will fix as soon as I finish setting up the new pc

new update should fix this