With what device did you record and can you see your activity on other platforms?

Hi Jan,

Thanks for your reply. 
My device is a Edge 820. I am not able to see the activity on other platforms.

Before the ride is transferred to Strava it must be uploaded to Garmin Connect first. If you don’t see it there you should start the Edge again and wait for it to sync or you trigger a manual sync on the Edge.

If nothing helps you can connect the Edge to a PC, copy the fit file for the activity and manual upload that file to Strava.