So I just visited all 27 of my cities. Searched for and collected Incidents on all of them. On 26 worlds there were at least half a dozen Incidents each, with most have in the 8-12 range. On the other one there was a single Incident. One. And guess which city was the only one on the event quest asking to collect 3 Incidents? Yep. That one world. I even went back after visiting 17 other cities, which took over an hour. Still no more Incidents.
Now, does this happen every time I have a quest requiring the collection of Incidents? No, of course not. But it happens pretty frequently. I normally never have this few Incidents in a city unless I've just collected there, or haven't visited it in several days. Neither is usually the case during events, and they have not been the case specifically in this event (Spring 2021). And it has happened several times during this event in multiple cities. I don't know why it happens, and I'm not claiming that Inno designs it that way on purpose, but it is very strange how often it happens. And anyone who is familiar with my posting history knows that I am generally one of the first to downplay alleged discrepancies with the various RNG mechanics in this game. I have noticed this happening off and on from the time that Incidents were introduced and then required for quests. Again, strange.