I ran through Katzenstein's Lab with two other people. All 3 of us were getting updates throughout the dungeon, as we expected. At the final turnin, to talk to Watson back on the Scotland Yard roof, the other two were able to do so successfully. As soon as I left Katzenstein's Lab itself to talk to Watson, it reset back to "Talk to Watson in Katzenstein's Lab" -- the first step in the dungeon -- and of course, he was no longer there, as we had already completed the dungeon. :(
I ran through Katzenstein's Lab with two other people. All 3 of us were getting updates throughout the dungeon, as we expected. At the final turnin, to talk to Watson back on the Scotland Yard roof, the other two were able to do so successfully. As soon as I left Katzenstein's Lab itself to talk to Watson, it reset back to "Talk to Watson in Katzenstein's Lab" -- the first step in the dungeon -- and of course, he was no longer there, as we had already completed the dungeon. :(
I almost every single dungeon, everyone must all talk to the first NPC to update their "external" quest. The updates you saw were only the "internal" quests. See my post to another player explaining the same concept, just a different dungeon.