Hello all,
Garmin Express would not always auto-magically sync my runs, which was of course maddening because the manual sync button has been removed. While Garmin Express would detect when my watch was plugged in it seems that when I had an external flash card reader also plugged in the sync Garmin Express would not correctly sync the watch. Remove the card reader and everything syncs as intended. Other USB devices did not cause this issue. Just the flash card reader.
Just an FYI if it helps anyone else.
Cheers,
Edward