We reported a new bug in which FIT data with negative values is rendered as ZEROs on the Web graphs (but work as expected for both iOS and Android GCM).
Here is another new BUG that only occurs in the Web view.... I have a data field that writes custom FIT data. I run that on both my EDGE 1050 and on my EPIX Pro Gen 2 watch. In the WEB version of Garmin Connect, all those custom graphs show up in the EDGE 1050 activity, but not in the EPIX Pro activity. They do show up fine for both devices in iOS and Android GCM.