Data lost/skipped/missing. BT syncing broken?

Not sure whether this is a device, a VAHR, issue or a GCM issue. But something is really askew with syncing. I was reviewing the last few weeks on Today view in the web version of Garmin Connect and noticed that many chunks of data are just missing. But it's inconsistent and not everyday at all. Example: I go on a 10k run, the activity is recorded correctly and is synced and can be viewed and HR is going be up at 160 or so, etc. But in the Timeline view of GC the HR is just normal sitting at a desk rate, there is no movement recorded either. Another is that in a day I could do, say, 15000 steps and this will be shown in GC summary, but again in the Steps Detail chart only a portion are shown. Big chunks of blank. What's really annoying is the trends over time are way off, particularly the HR. These blanks affect sleep data too.

The data on the VAHR is correct, but they're only totals. The same erroneous data is, of course, displayed on GCM too.

I suspect it's the Bluetooth sync. I'm going to try and only use the cable for a while and see if it's any different.

Anyone else getting this?