Activity not syncing to Garmin Connect App from Instinct 2 Solar

I recorded two activities (#1 and #2) today morning. #2 got synced to my Garmin Connect mobile app. #1 is still not synced. I tried rebooting both phone and watch but still the sync didn't happen. I also tried recording another activity (#3) and this one got synced. But #1 is still not synced. Any suggestions on how to get it synced?