Fitbit Sense stuck in a rebooting loop

[GeraldB88]

Very disappointed that my Fitbit Sense went into a rebooting loop about 14 hours ago. It started with rebooting every 2-3 minutes but now it reboots every 15 seconds or thereabouts. I have done a hard reset thinking this may fix the problem but with it rebooting every 15 seconds it is impossible to do the setup again. I bought my Sense in mid December 2020. I have notified support via a chat but they can only give me a case # and told me to wait for someone to contact me, Very disappointing indeed give this is the falgship model and I just become a Premium member so as to enjoy the stats tracked by the Sense. I note on the community page there are many Sense users having the same problem.

Moderator Edit: Personal info removed

[GeraldB88]

Yes. The replacement they sent me has worked great for about the last year now. 

[braggit13]

Hi - I too have had the same problem as lots of others with the 'reboot' loop - I reported it to the support team and they did send me the latest steps for initiating a factory reset - see below:

• Don’t plug the Fitbit device into the charging cable.
• Press and hold the button for about 8 seconds until the screen turns off
• After the screen turns off, you will feel a short vibration. When you feel the vibration:
• Release the button and immediately press and hold the button again.
• Wait until the blue logo appears, then disappears.
• Immediately release the button and then immediately press and hold it again, until you feel a vibration.
• After you feel the vibration, release the button. This vibration indicates you have started the factory reset.

After that, set up your Fitbit Sense as a new device.

That said, I've tried this a couple of times now a set up the Sense as a new device, then it gets to the firmware update stage and then starts this cycel all over again!  Persisting with contacting support in the meantime...