I may have some new insight in the "My lich does not die even though I have the right combo" bug.
We were doing a mission, several Liches appeared shortly after eachother, most went fine, one was left. Mine did not spawn, yet curiously I did get messages from my Lich as if he/she/it was there fighting with me. A fellow tenno downed his Lich and died, seemingly having the wrong combination, he claimed in chat however that it showed him he had the right combination, yet the Lich killed him as if he did not. Weird, but by now I was aware this bug existed.
So far nothing new. Except maybe the mixed up messages.
When I returned to the orbiter however and checked the anger level of my Lich, I saw that it showed a new attempt, confirming my second rune. But also showing me the third rune was incorrect. I did not fight my Kuva Lich that mission though. What I think happened is somehow his and my Lich got mixed up in code (wrong scope for a variable maybe?) allowing him to fight and parazon him, but somehow making that attempt be recorded as my attempt, which failed since I had the wrong third rune.
I hope this new info helps nail down those gLiches (sorry, had to make it)
In the meanwhile, can people who have this bug try and run the mission solo? Maybe if it works then it could help support the theory that it is related to mixing up data from other players liches.
This does not seem to be the case, solo missions can still get this bug it seems