Fitbit does not show your steps in the 7-day total and not counting them against challenges from any third-party application.
For Fitbit, Garmin Connect, and a few other sources, we get immediately notified whenever you sync or add a new activity on their end, and thus, the sync button usually does not find anything.
With a Pro Account, you can do a Historic Sync by editing your Fitbit task and selecting Historic Sync from the bottom. This will allow you to select the dates you want to copy into FitnessSyncer and the operation will occur in the background. It could take a while to complete and it is recommended that you not change the settings while it is in progress.
Fitbit only generates proper TCX files for activities with GPS data, and as such, we do not have the rich data required to be useful at services that require detailed activity data.
Fitbit allows us to either upload steps or distance, and infers the other based on the data in your account. To control whether we upload steps or distance, change the “Prefer steps over distance” setting under Profile.