This is usually a case of we don't have permission to see the data or the wrong Fitbit account is connected to us, perhaps the account you use to sign into your Fitbit app on your phone is different than the one you used to connect Fitbit to KrowdFit. 

We can start by checking within the Fitbit app on your phone,  account > manage data > Manage third party apps to see if KrowdFit is listed in there with permissions granted. We require: sleep, settings, nutrition, activity, heartrate, profile, weight, location. In order to get the Fitbit summary data we require from their API.