Somachord tones not appearing during the Sacrifice quest.

[(XBOX)Tolman05]

I was going back through the Sacrifice quest after seeing that were tones for it and because I guessed that "To take its pain away" would be one of the tracks you would get for getting all the tones. So I looked up a guide and got 2 tones fine enough then remembered that the Deadlock Protocol update had changed the corpus level you encounter Umbra on so I found another guide for that tone and they all say to look under the stairs in the next room after defeating Umbra. So I looked and there was no tone. I thought maybe because I didn't play the quest for a long time. So I replayed it and still nothing. Is this known? Is this a simple, fixable glitch? Am I just unlucky?