I have 3 rings of lich and boots which give me 4 pieace bonus then when I equip nerien'eths forsaken staff or sword of the lich nothing happens it doesn't count it as a 5 pieace.
I go from 3 to 5 lich with DW swords and it worked ok as of last night. I can proc it, then switch off that bar with my regen still going on the 3 piece bar.