Got Herald but no Diablo in TZ CS

Diablo did not spawn as expected in terrorized Chaos Sanctuary tonight.

I've double- and triple checked that all seals are open, and there is nothing left of the seal boss packs as far as I can see. So I'm trying to figure out what's going on.

My procedure: I went counter-clockwise through the seals, however, before spawning Infector of Souls' pack a Herald spawned, who was itself a Venom lord (with pack). After killing them I spawned Infector's pack, killed them, then went on with Lord De Seis and finally Grand Vizier of Chaos. And opened all seals along the way of course.

Then nothing more, no "Not even Death..." message, no Diablo.

Ideas about what could've happened:

1. I'm not entirely positive I killed every seal boss, I only cleared all visible monsters in the packs - I'm running a lvl 90 FoHdin with lvl 25 Conviction so packs disappear pretty quickly (P1 online).
2. Could it be related to the Herald, maybe it somehow replaced Infector of Souls so that he did not spawn with his pack? Seems unlikely, but still an hypothesis.
3. Something else with the Herald mechanics messing things up?
4. Maybe Grand Vizier flew out and hid above the lava, somewhere out of reach? I did walk the Edge of his entire wing of CS, hurling holy Bolts out in the Void, without results.

When searching around I found a thread about Dclone sometimes preventing Diablo to spawn, but that seems still different.

Has this happened to anyone else?

IME, its usually the Grand Vizier of Chaos who has gone off on an adventure offscreen

Kakumba wrote: 3 months ago

IME, its usually the Grand Vizier of Chaos who has gone off on an adventure offscreen

This sounds plausible - it has never happened to me with Grand Vizier before, but often with other flying critters. If this is the explanation it likely had nothing to do with the Herald. On the other hand, I fired at the pack immediately when spawned and it was gone in 2-3 FoH strikes, so it seems that Grand Vizier would have to be both fast and quite the coward to actually get away.

However, I do believe that each of the seal boss packs dropped at least one rare, which suggests (but by no means ensures) that the bosses were actually killed. As I mentioned I didn't visually spot any of the seal bosses in their packs, due to the fact that the FoHdin playstyle does not really depend on precision targeting

Anyway, I'll leave it at that for now, and we'll see if anyone else has evidence to add.

Apparently there is at least one other apparent bug around having to do with CS and Heralds.