If you are trying to find the group by using the name of the Event to search, then either the name of the Event was changed, or the name of the group was changed. If you are searching the full name of the Event including the event date, then it's possible that the date of the Event was changed. Any changes to the Event will not affect the naming scheme of the existing group that it is associated with. Vise-versa, the name of the Event Attendees group will not affect its association with the Event.

If you cannot find the name of the group that is associated with your Event, then please Contact Support and reference this article.  Luminate Support will need to find this information by looking at the back end.