Bug Report:Sync to Garmin Connect is very slow after a long ride

When I completed a long ride (say 100km or more), 840edge syncing to the garmin connect app was very slow (20 minutes or more) and sometimes I needed to restart 840edge to successfully sync the ride data to the garmin connect app(it also takes a few minutes). My firmware version is 21.17, and I see a lot of people on the forums are having the same problem, so I wonder when this BUG will be fixed?