Difficulties with SpO2 and brightness-Charge 3

[SnailsPaceFarm]

When the SpO2 service was added to Charge3 by Fitbit, it worked well. The graph showed up daily in the Sleep report for the previous night. Reports then became sporadic and are now nonexistent. I've tried loosening the band, tightening the band, nothing helps. My screen is also so dim it's nearly impossible to read in daytime room light, impossible to read outdoors and can only be seen vaguely in pitch dark. I've tried restarting many times, no improvement in the screen or the SpO2 log. Is there a fix for this or are these parts of my Charge 3 worn out after 3 years of use?

Moderator edit: updated subject for clarity

[EdsonFitbit]

Welcome to the Fitbit Community, @SnailsPaceFarm.

I'm sorry to hear about the difficulties you experienced with your Fitbit Charge 3. Thank you for trying to get them resolved before contacting us.

If you haven't done so, please try to change the brightness settings to see if there is any improvement. In addition, please make sure Sleep Mode and Do Not Disturb (DND) are turned off. For instructions on how to navigate your Fitbit device, please visit this article.

You can also change your clock face by following these steps.

Regarding the issue with the SpO2, I would like to clarify the Charge 3 tracks Estimated Oxygen Variation instead of SpO2. For information about the difference between them, please visit this article and open the menu "What’s the difference between estimated oxygen variability and SpO2?".

Our team has recently released a new version of the Fitbit app (3.52.1 iOS and 3.52 Android). For instructions on how to check your current version and update, please visit this article and open the menu "How do I update the Fitbit app?".

Hope this helps.