I'm sorry but Strava is just wrong, as in completely whacked out.
Polar GPS: 1115 ft.
Polar Flow Website: 1115 ft
Training Peaks: 1115 ft
Ride with GPS: 1125 ft
Strava: 1824 ft
I didn't ride over 800+ ft of bridges. Stava doesn't know what to do with Polar altitude data.