Fitbit Sense randomly spiking heart rate, "Pulse while sleeping", unnoticed by myself,

[Emberfre]

Hi!

So ive had Fitbit Charge 4 for about a month, loved it, so I got myself the more expensive Fitbit Sense.
This night, watching the rest sleep from the sleep quality feature, I noticed something very wierd.

Going to sleep my heartrate was about 65-70 while I just got to bed.
I fell asleep somewhere around 01:33-01:45. But around when I get to bed, theres alot of moving around, left side, back, right side, back, right side, sleep.. Lets just say I need to find the perfect posistion. Including hands moving putting weight on my wrist from the side, below (pushing fitbit away from wrist) etc.

Ok, so heres the deal.

Timestamps:

• 00:30-01:37 - 68 to 63 bpm.
• 01:38 - 79 bpm.
• 01:39 - 93 bpm.
• 01:40 - 111 bpm.
• 01:41 - 139 bpm.
• 01:42 - 141 bpm.
• 01:43 - 113 bpm.
• 01:44 - 55 bpm.
• 01:45 - 56 bpm.
• 01:46-07:30 - 46 to 59 bpm.

(I wear my Fitbit quite loose i suppose, can fit two fingers between the strap and wrist)

So, either I dident notice my heart racing to heart rates to the point I have while heaving a heavy workout, or the fitbit got disconnected from skin and flipped out, or I had some sort of episode of afib (Anxiety worrying unrealistic worst case scenario here, god I hate anxiety).

Ive never had this high bpm or spikes on my "Pulse while sleep" before.

30 years old, healthy, no diseases. (Except whats causing me to write this, anxiety)...
So, have anyone else experienced the Fitbit Sense flipping out, cause Ive noticed before that the fitbit has counted more bpms than im experiencing, Ive been standing up looking at my fitbit and its going up to 110, while I can feel my pulse being around 80-90.

Bottom line is basiclly:
Anyone else experienced this with the Fitbit Sense?
Should you be able to fit two and a half full fingers between the strap and the wrist? Should I tighten the strap?
What do you belive is going on here?

[SunsetRunner]

Don't worry, @Emberfre !

Looking at your heart rate graph and the time you went to bed, I would bet there is 99,99% probabilities that that "heart rate" spike is a Sense artifact (false HR spike) and there is nothing wrong with your heart!!!

The same happens to me all the time and the pattern is exactly like yours. I realized that all those hand movements just before going to bed and laying down are the cause for that artificial spike. Sense's heart rate readings are very sensitive to hand movements, even more when its band is not tight enough (but not too tight!), but even then.

[SunsetRunner]

@Emberfre  if you would like to know more about Sense's Heart Rate accuracy and reliability, which are an old Sense issue, I suggest you read this post , this post  or this thread , besides Fitbit Sense Help pages, although these don't mention issues like these false spikes, as far as I can remember.

[Karenpvfc]

I’m having this too and with a family history of heart issues it’s worrying. I do believe it’s inaccurate but Fitbit don’t seem to want to address it and keep sending generic replies about what can affect HR.