I used my garmin ant usb receiver on a new computer (mac) for the first time today and it connected with my device, said the upload was successful, and said it was paired with garmin connect, however the ride isn't showing up on garmin connect (or strava - accounts linked). Any ideas? Thanks
You might go back into Garmin Express, select your device from the drop down, click the device link on the right, and then click the button to change the Garmin account associated with the device. Re-enter your user-name and password. Be sure to use exactly the same username/password you use for logging into Garmin Connect to look at your workouts.
Once you've done this, create a test activity and then upload that. If it works, then you can go through the steps to re-upload your activity.
