Event Removed from ZwiftPower

Our AHDR Bacon Rolls with caffEine ride/race at 5.50AM AEDT disappeared from ZwiftPower this AM just before the start. It was there with riders listed until just before the start, & listed in the events.
When it was selected at 5 minutes before the start (from still being in the list) we were getting “Could not find Event”. A short time later the event disappeared from the Events list too.
There were 480 riders in the event. Any idea what happened & how we can stop if from happening again?