Air France flight 55, which was supposed to depart IAD for CDG on Jan 13, 2019, got delayed several hours due to the snowstorm. A few minutes before midnight, the flight suddenly disappeared off of FlightAware, as if it no longer existed. There was an error message about an issue with the flight/date pair, but that message was short-lived.
15 minutes later the flight came back, now en route. It departed on the originally-scheduled date.
I started this post to ask, “How can I track this flight”, but it is now a report of a strange bug. Has this (mis)behavior been noticed before?