I noticed a 44-minute activity recorded on Strava shows up as a 3-hour activity on my iPhone's fitness app. I suspect it might be due to the Strava API sending out an incorrect "end time." I noticed that the fitness app displays the recording time, both the start and end. It shows the end time of the activity as the time when the activity was "finished" or "saved" on Strava, and not when Strava identifies as the end of the activity, correctly classifying the rest of time as wait or a period of inactivity on the app.
It could also be implemented incorrectly on the Fitness team's side, but I thought it would be best to do it here as well.