SpO2 missing on my new Fitbit Versa 4

[W8djp]

So I just picked up my Fitbit sense 4 yesterday,  prior to that I had another Fitbit watch that had the spo2 sensor and it was reading fine however the watch could no longer hold a charge, the sense 4 is the same style of Watch, I have fully charged the watch, I have updated the software, I have checked the settings to verify that nothing changed in the app as far as granting access for data in the background, I have the spo2 watch face on the watch and I wore it to bed last night, I got up this morning and normally I would have a 02 reading on the old watch apparently this one you have to sync with your app, I have synced the phone with the watch it's been well over 2 hours and still no O2 readings, I went in and removed the current watch face back to a non spo2 face and I also removed the tile because as stated I don't need to run both, I reinstalled a new spo2 watch face and synced with my phone and still no spo2 reading...what's up?

Moderator edit: updated subject for clarity

[ManuFitbit]

Welcome to the forums @W8djp. 

Thank you for providing the details regarding this difficulty that you are experiencing with your Versa 4 and the steps in order to fix it.

Please give a try at the following steps:

• Make sure that your device is up to date: How do I update my Fitbit device?
• You must get at least 3 hours of quality sleep. Data is only collected when you’re still. If you move a lot during your sleep or the sleep session is too short, you might not get SpO2 data.
• Charge your Fitbit device to make sure it’s able to collect data throughout your entire sleep session. Note that you may have to charge your Fitbit device more often when using an SpO2 clock face or app.
• You must sync your Fitbit device with the Fitbit app before the clock shows your SpO2 data. Note that it may take around an hour for your SpO2 values to appear after you sync your device. For troubleshooting syncing, see Why won't my Fitbit device sync?
• Turning off any SpO2 clock face or app permissions can cause the feature to stop functioning. For instructions on adjusting permissions, see How do I install and manage apps on my Fitbit device?
• Your Fitbit device must be able to consistently track your SpO2 data:
  • Wear your device slightly higher on your wrist.
  • Make sure your device is in contact with your skin.
  • Your device should be snug but not constricting.
  • Tattooed skin can impact the accuracy of the red and infrared sensors on your Fitbit device.

For more information, see How do I track blood oxygen saturation (SpO2) with my Fitbit device?