I’ve had the same issue - Olympic chase race 2 Laps of Makuri at 10pm U.K. time. Finished race but it didn’t record result. I stayed in the world and saved ride. It appeared on activities list in companion but I’m not listed as finishing race. Loaded ok to Strava and connect but didn’t save result to Zwift power.
Very frustrating as I bust a gut to stay with lead group!