We’re looking into reports of the Protection Paladin 4 piece bonus not properly casting Judgment when it should be. The intent of this bonus is that it does cast a real Judgment when it triggers - debuff, Holy Power, and damage. Also worth noting, in a coming build, its internal cooldown will be increased from .1 seconds up to 1 second. This will help keep the bonus’s power from scaling out of control when tanking large numbers of enemies at once, while still rewarding the intuitive behavior of “trying to block as many things as you can.”
With regards to the Retribution 2 piece, it is a bug that the set’s Seraphim overwrites an active Seraphim. The intent is that it will extend one, so the value of the 2 piece is consistent whether you are running Seraphim or not.