Strava App on Apple Watch total run time different to Strava app on iPhone

[SBRunner]

Since subscribing to paid version of Strava I have noticed errors in my run activity time. This morning I used the Strava app on my Apple Watch to record my 10km run, pressing start at the beginning of the run and not stopping until the end of the 10km run. My watch recorded 1 hour and 5 minutes. (Incidentally my friend ran with me at the same pace using her garmin watch and recorded the same overall time - which recorded correctly to her Strava app). When the activity synced to the Strava app on my iPhone it shows a moving time of 58 minutes and 47 seconds. It knocked over 6 minutes off my running time! When I viewed analysis the elapsed time recorded as 1 hour and 21 seconds! Two very different times and still nothing like my genuine time. I do not know why the app is making me appear quicker than I am, but it’s been inaccurate like this on all my runs recorded since I started paying for Strava. 
How can I get the Strava app on my watch to sync correctly with the Strava app on my phone? The Strava app on my phone isn’t also recording at the same time. I don’t use the health app on my watch to record the time, only the Strava app on the watch. 
The worst part is that I can’t edit the time in the activity to show the correct time, so people are congratulating me on a PB that I didn’t honestly achieve! 

[Bryant · Accepted solution]

Hey @SBRunner,
Thank you for writing in and providing these details.
Normally when you experience different times that your friend, this could be signs of your GPS signal not being strong during your activity.
I recommend checking our support article that reviews this topic here.

As for troubleshooting steps you could try, reinstalling the Strava app on your Apple Watch.

Please follow these steps:

1. Log out of the Strava mobile app on your iPhone.
2. Use the Watch app located on your iPhone to force an uninstall of the Strava Watch app. Note that it may take some time for the app to be fully uninstalled from the Watch face.
3. Confirm the app has been uninstalled from the Watch.
4. Uninstall the Strava app from your iPhone. *Please make sure not to delete your Health data as we now only sync the last 30 days to the Health app
5. Force close all apps on the iPhone.
6. Restart the Watch and iPhone.
7. Download and install the Strava app on the iPhone.
8. Confirm you are logged into the Strava app.
9. Confirm the Strava app has been installed on the Apple Watch.
10. Unlock the display on the iPhone and load the Strava Apple Watch app.
11. Watch for and approve prompts on both devices.

Please let me know if that helps.