With my Edge 520 Plus, discarded rides don't appear to be discarded. When I plug the 520 into my computer to charge/sync, the rides that I had discarded are uploaded. Not sure if this is a bug with the Edge 520 or Garmin connect software. The same thing happens with Fenix 6 Plus.
This is super annoying because I end up with lots of duplicate rides. I ride with both 520 plus and my Fenix. I usually save the ride from the Fenix and discard the other.
Anyone else encountering this?