Apart from the Pace chart missing from the Garmin report, the overall time duration and pace are different. It appears that GC is using overall duration, while Strava uses movement time.
Tx. I had a look at that swim and there isn’t a velocity trace but it does have “lengths” which is something I haven’t seen before. Looks like Strava is using that to plot velocity. I can probably do something similar.
Intervals.icu now constructs a velocity stream from the lengths data if present. So you get a pace chart like Strava. This is also used to calculate moving time which for this example comes out to within a second of the Garmin Connect value.
The pace chart should probably be secs/100m or something for swims right? Instead of km/h.