I used long time to old Agent version with my 2 x 910xt + Fenix 1. I'm happy with that manual sync for Fenix 1. I update Garmin Express to my work and personal PC. First I think this duplicate data caused for data transfer from work PC morning and then evening at home. Now I notice if I use only my home PC it still transfer gpx and fit data from my Fenix 1 device (firmware 4.80, GarminExpress ver.3.2.29.0) to Garmin Connect cloud.
Is this common issue?
Does Express application some hidden setting?