It’s not a bug – it’s an undocumented feature.
3R LaGuardia Loop Flat Race - 2 Laps (6.7km/4.2mi 54m)

Tonight’s race. I showed up with 4 minutes to race time. Showed 27 racers and only me and one other guy rode the race until he quit. It kept showing me moving up places until it showed 1st. Which I’m assuming was the end of the race?? I kept riding and the distance meter on top would never change. Not sure what happened other than it shows me with a gold in DNF? I rode almost 30 minutes and the rest rode less than 10? Never had that happen before.
Billy Wills wrote:
Tue Jan 15, 2019 6:05 am
3R LaGuardia Loop Flat Race - 2 Laps (6.7km/4.2mi 54m)

Tonight’s race. I showed up with 4 minutes to race time. Showed 27 racers and only me and one other guy rode the race until he quit. It kept showing me moving up places until it showed 1st. Which I’m assuming was the end of the race?? I kept riding and the distance meter on top would never change. Not sure what happened other than it shows me with a gold in DNF? I rode almost 30 minutes and the rest rode less than 10? Never had that happen before.
NY is notoriously buggy. You were not recorded as finishing by zwift. That is usually caused by a client side network issue but problem could be zwift side.

Drop your race log file in https://zwiftalizer.com/ and see what it says about your connection.