For the second time in as many weeks, I have tinkered with a series Story Map, finished my changes, and gone to an incognito window to test whether the public could access it. They couldn't. I was unexpectedly blocked by a the "please sign in" request. That usually means that some component of the overall Story Map was not shared publicly. I was able to narrow the problem down to a map app feeding my Story Map. After checking all of my sharing permissions a couple of times, and rebooting once for good measure, I got the same message, gave up and went to bed. By the time I woke up, my Story Map had fixed itself and could be opened from an incognito window. Elves? What do they know that I don't?