Yes, i can confirm sleep data is not available (missing) in GC for some reason since few days. I thought it is only problem on my device, but i see there are other guys with the same problem. hope GARMIN to fix it soon.
Just to share how I fixed this problem: I just installed the new Garmin Connect app (beta), then deleted the watch (from More->Garmin devices), then and re-added the watch. Now all health stats is displayed in GC.
