My watch and Webscorer times match within a second or two for each run except Thom B.
It’s confusing, but Strava isn’t really dropping anyone’s time. Strava shows estimated moving time in the scroll feed. This doesn’t include time you are stopped (or when Strava thinks you’re stopped), i.e. a water or bathroom break. When you open an activity from the feed you can view detailed stats, including elapsed time. The elapsed time matches both Webscorer and my Suunto watch time, since I never stopped either timing device mid-run. Tagging a run as “race” in Strava will show elapsed time and elapsed pace in the feed instead of moving time and moving pace.