I appear to be unable to progress in the Aza Companion Quest "Stabbing at Shadows." I am at the objective, "Rendezvous with Severin" on Cloister. I went to their location, I went through their dialogue and then fought the Sentinels that ambush you and then nothing happens. From what others have said, a conversation with Aza is supposed to automatically trigger to progress the quest, but I never got that conversation and now I am just stuck at this part and unable to progress. I have tried leaving the planet and returning, changing companions, reloading the game. Nothing has worked. I was using Tristan as my second companion when I was doing this quest and defeating the Sentinel ambush triggered a conversation with him, so maybe that interfered with the quest? I am just speculating.
I haven't been able to do any retesting on a different character as the quest is a bit far into the game, but based on what I have seen others say about the quest, it seems like Aza needs to loot something from Severin's body and that looting Severin's body yourself too quickly could interfere with that. Again, I don't know for sure if this is what is happening, but it seems plausible.
Hopefully this helps and there's a fix/workaround/solution to this soon!