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Strava uses moving time but has a generous cut off for what is "moving" and also doesn't interpret the data from most GPSes well at all. If there's any GPS dropout during the run (say for 5 seconds or so) Strava will claim that as stopped time despite there being cadence/HR/running-dynamics data there for that period and the subsequent GPS point appearing 15m down the road in line with running at 12kph for 5 seconds.
As for distance, that's just the whim of the GPS data and the smoothing algorithms that get applied. Again, Strava tends to be more generous and doesn't smooth things out as much. Others will get rid of obvious glitches (like suddenly moving 400 yards NE for a few seconds before instantly moving back - Strava counts it, others don't).
I did my usual run but used Strava and Nike Run Club. Distance and average speeds are different on both. Strava makes it look like I ran further and faster, Nike went the other way.