It would be hard for anyone to know without more details.  Could you provide some specifics about what type of data is different?  Different files altogether?  Different power, distance, time, etc...?  Some things like time can look different due to how strava and other systems calculate and display moving time versus elapsed time.  Power can be calculated differently depeding on those same things.  The more detail you can provide, the better help others can provide.

I get wrong distance, speed, and elevation on road ride.