How do you get third ascendency?

I'm so confused. I killed the boss in cruel act act 2/3. Both dropped regular trial invitations. I failed both on first try (lol). I've since dropped more invitations, redone both trials and completed them but there's no ascendency trial at the end? Do you get the third ascendency from doing higher trials dropped from maps or something? My quest log still says "search traitor's passage" but I've full cleared it like 3 times. I don't know if this is a bug or I'm just missing something here