It turns out that making sure the data is fully sync'd is part of the game! Count.It "closes" the leaderboards in order to accurately determine winners, meaning the total or average score on your group's leaderboards always represent the final standings for the end of each week and monthly/PRO challenge.
What that means: the result is that it's very possible for users to sync their tracker after those timeframes have ended, and end up with data on their Logs page that is not reflected in their score on "closed" leaderboards. (example: assuming your group is running a Monthly challenge for June 2020, all data reported for the week 06/15-06/21 might not appear on your Weekly Leaderboard if sync'd late, but would be reported to your Logs page and will count for your overall Monthly/PRO Challenge!)
So, be sure to sync your device regularly and especially on the last day of your challenge to receive full credit!
Please note: Count.It allows for a 12 hour syncing grace period at the end of challenges. Count.It will credit any activity logged as long as that activity is assigned to a day that is within the challenge window. However, if user has activity data within the challenge window, but fails to sync within the 12 hour grace period, then they will not get credit for that activity as the challenge has officially closed.
Example: Your group's challenge dates are June 15 - July 15. Which means your challenge ends at midnight (12AM) on the 15th in your group's timezone. You will have until noon (12PM) the following day (June 16th) to sync all your data tracked through the 15th, at which point the leaderboard recalculates and the standings are finalized.