Charge 6 not syncing and sleep not tracking

[rachewin]

I just bought a Fitbit Charge 6 yesterday to replace my Versa 2, which stopped recording sleep data. Before giving up on the Versa 2, I spent a full week troubleshooting and finally concluded the sensor had died.

Naturally, I set up the Charge 6 right away—looking forward to finally seeing accurate sleep tracking again. But this morning… no sleep data at all.

Every other metric seems to be working fine, but the two features I care about most—SpO2 and Sleep Data—are still missing.

Is there a fix, or did I just swap one problem device for another?

[KatieLeigh]

I have the same issue with my Charge Six. Customer support said I needed to resync it when this happens. I did that twice, worked for a couple of hours, and the it stopped recording sleep data. I’ve given up on it. I’m in the market for another brand. I’ve had it with FitBit.

[Waterlilymd]

My sleep tracker only works some of the time. It’s really frustrating.
Sent from my iPhone

[RiekoC]

Hello @rachewin 

I've seen some users report that it took hours for their sleep data to show up, which isn't what I experience. And, I'm guessing, that's not the way it worked with your Versa 2. 

What troubleshooting steps have you tried so far to see if you can get your sleep data from last night? 

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Hello @Waterlilymd 

Please share with us the details of your sleep tracking issues. What troubleshooting have you tried? 

[rachewin]

I tried uninstalling and reinstalling the program on my Moto g 5G.

I checked to make sure all my software on phone and fitbit is up-to-date.

I reset fitbit to factory settings. 

I disconnected Bluetooth, powercycled my phone and fitbit (after doing a force stop), and then reconnected. 

I probably did other steps I cannot remember at the moment.

[RiekoC]

Hello @rachewin 

Thanks for responding so quickly and sharing the troubleshooting you've tried without success. 

Did you have a chance to try manually logging your sleep in the Fitbit app to see if that generates your sleep data? If you've already done a factory data reset on your Charge 6 today, don't try this. There won't be any data since it was already deleted. 

Just to confirm, you don't have any tattoos or scars on the area where you wear your Charge 6 and you see the green light (optical heart rate sensor) on the back of your Charge 6, correct? 

Have you tried wearing your Charge 6 on the inside of your wrist to see if you get any sleep data?

[rachewin]

No scars or tattoos. I will try wearing the Charge 6 on the inside of my wrist tonight. I will try manually entering the data tomorrow if nothing shows up when I sync.

[Waterlilymd]

After all you did, did it work?
Sent from my iPhone

[rachewin]

After working with Fitbit customer service, my sleep data from the past two nights finally appeared on my phone this morning. Hopefully it keeps syncing reliably from here on out.

[ShellarI]

You are not alone. I have been facing a very similar problem with my Fitbit Charge 6 since June 8, 2025. Syncing became unreliable, some data (like resting heart rate and sleep) disappears after syncing, and the device sometimes even shuts down at random battery levels.

I’ve already created a detailed thread here:
 Fitbit Charge 6 – Sync/Pairing Broken Since June 8, 2025 (Device Unusable, Support Unresponsive)

Maybe our cases are connected — looks like more and more Charge 6 devices are affected after the recent updates.