Sense SpO2 stopped working

[yy3]

Bought a sense a week ago and everything was working fine. I was able to see 5 nights of spO2 data in app and on clock face. But the last two nights, there was no spO2 data in app - it's says "no data" on health metrics - and the clock face shows "--%". I didn't do anything differently at all. Does this mean my spO2 sensor is damaged? I have tried reinstalling the spO2 tracker app and turning off and on my sense watch. I only see green light at the back of my watch. 

Moderator edit: subject for clarity 

[PB1325]

I bought my Sense several months ago.  Have yet to get a SP02 reading.  I am lucky if I get any Health Metric readings at all

[yy3]

Thanks for sharing. Did you try to repair or replace it? Was there support from Fitbit? 

[PB1325]

Yes the support was from Fitbit. I talked with them several times and the
only thing they could tell me was to uninstall and reinstall the app. If
that did not work to set the Sense up again. Nothing has worked. Right
after the 30 days it quit showing any information on Health Metrics at
all. It does nothing more than my cheap health monitor watch does.

[yy3]

My spO2 sensor came back alive. I changed a clock face, uninstalled the spO2 tracker, restarted the watch by holding the button for 10s, reinstalled spO2 tracker and finally changed back to my original clock face. Something in this sequence must have triggered the sensor to work again. Hope this helps someone.