@guitargeekrich with Strava there is a different story. Strava uses GPS data (if available) for distance for some watches while for others it uses distance reported by the watch (with option to substitute it by the GPS distance). It depends on their agreement with specific brand. For example, there is know agreement between Garmin and Strava to use Garmin's reported distance so both in Garmin Connect and Strava the metrics are consistent. Fitbit doesn't care much enough to provide proper Strava support so Strava system processes incoming data same as for other "less-serious" brands.
What you see on the watch is a result of Fitbit's distance/pace computation based on stride, sensors, steps. All manufacturers do that (for running, using GPS only is a no-go) but Fitbit seems to be most inconsistent of all I've been using. See that I don't say "inaccurate". First thing I require is data consistency which means that running same route multiple times will result in the same distance (with tiny negligible differences) as consistent data give a proper reference point to observe progress/regress of fitness. This is something Fitbit has been struggling for years and in my eyes it isn't a runner's watch (or sports watch in general).
