Protection blocks some damage from the warden's sonic boom attack

I'm not sure if this is intended, but according to the changelog the warden's sonic boom attack now ignores armor but not its enchantments. My armor has protection 4 and it only dealt 1 and a half hearts when it should have been 5. If it's supposed to ignore armor I assume it should ignore the enchantments on the armor as well. This is on Hard difficulty and it barely damaged me.