I'm also seeing this weird bug on my Strava app when I record with my Apple Watch (it's fine if I record directly on Apple Workout and then sync it though). An hour-long activity ends up showing as 10 hours or more, with the start time being over 12 hours before I actually started. Did you ever find a fix for it?

I can only suggest that you use the native Workout Apps on the Apple Watch to record the activity and then sync that to Strava afterwards (you can set Strava up to do this automatically).  
 

This is the method I use and never have any issues across a broad variety of workout types.  
 

Let me know if this solves your problems or if you need any help with the sync to Strava   

jxccnta - the only workaround I’ve found is exactly as BryanC suggested, to stop using the strava app on my watch and use the apple workouts and then import them in into strava. Since I’ve been doing this I haven’t had the issue.

I’m glad the route I suggested is working for you. 

This is also happening to me, intermittently.  Cropping it in Strava after the fact will correct the data, but it is very annoying! 

Recording natively to Apple doesn’t work, because they don’t yet have an e-bike mode. 

You can record as a ride and then change the activity type within Strava.    I think that should work. 

Not a great work around, because I’d have to do it at least 2x daily and if I forget I’m messing up the leaderboards for everyone else. 

Then maybe the issue is with Apple.   Have you asked them for an e-bike app?

i had this issue yesterday. logged a 2 hour walk, approx 4hr elapsed time, the strava app on apple watch elapsed 23 hours instead, and it messed with my fitness data from the day prior. never had this happen beofre.