Inexplicable heart rate spike only in Zone graph

[Cyantaiga]

I've only had this device for about two weeks now, and this is the first time I've noticed this abnormality. My Active Zone Minutes graph shows a heart rate spike from 12:35am to 1:20am, while I was asleep. However, my RHR graph and my HRV graph have no indication of this spike, and my sleep stage graph shows me in light sleep for that period. Furthermore, there's no record of this spike in the "when you got your minutes" history (though thankfully it at least seems that this spike wasn't counted in my zone minutes, since the history adds up right). Is this a known issue with the device? Is there any way to keep this from happening? Normally I wouldn't care much, but since I'm participating in the WEAR study, I want to be sure that the information that gets sent is as free from errors as possible.

[LZeeW]

@Cyantaiga   Many users have been complaining about the phantom spikes in their zone minute graph for some time.  I get them, too.  It doesn't matter what Fitbit model you use, either.  I think it is an issue with the zone minute graph itself, not with the data.  My sleeping heart rate graph doesn't have them.  I don't think this will have any effect in the WEAR study.