Hi all,
My situation: I had been unaware I needed to upgrade to Express. Ant Agent had marked a week of runs as synced. When I installed Express, it didn't see them, but it did see new runs.
The solution: I was able to manually sync the runs to Garmin Connect with the file upload feature in the Activities section. The files are located in the ~/Library/Application Support/Garmin folder. In that folder you may have any number of sub-folders. My files were in Devices/[somebignumber]/History/date-number.TCX
These TCX files are what you can upload if you also have a gap between Ant Agent and Express. I hope that helps some of you. :cool: