Yesterday I completed 2 activities with my Fenix 3 HR. Both activities are stored on the Fenix3 HR, but did not sync to the garmin connect android app and website.
Garmin Support please check what is happening
I am having the same issue. I sent Garmin an email asking if they are having issues with Connect and app on phone. The reply I received was basically delete the Fenix pair it again and to also make sure connect is running current software. Did all that and still nothing.