To ensure optimal performance, user profiles are currently not generated in real time. This means that when a user’s event is received by the Insights API, their profile won't be immediately available to the Search API or to view in the Personalization simulator.
User profiles can take up to 3 hours to be computed, and once created, profile refreshes happen every 2 hours.
It's also important to note that Personalization only takes effect on returning users This means new users will see personalised results on their return session, not their current session where events are first recorded.