There can sometimes be a delay between when your activity shows up in your Dashboard and when it appears on the Challenge and Team Leaderboards. This is because these pages update at different times to ensure a smooth app experience.
Don't worry, your data is safe! As long as your activities have successfully synced to your Health Data history and appear on your Dashboard, your Leaderboards will update by midnight UTC at the latest. If you don't see your data right away, please check again the next morning.