Since about 10am this morning, the all day heart rate from my fenix 5 is showing at a steady 100bpm (with a couple of spikes) - and the 100bpm line actually extends all the way to midnight, even though it's only 14:40. On my f5 itself, the HR is being captured properly and the 'last 4hr' plot looks good, so it looks like this is something happening on the Garmin servers. Everything else is synced correctly, so I don't think it's a syncing problem.
Anyone else seeing anything like this? The only change I've made in GC today was changing my activity level back to 7 as somehow it had changed to 5.