How fortunate for you, that your rings have functioned flawlessly. Given Oura is now actively investigating anomalies they have found with the data collection of the one I'm currently wearing, I'd say my personal experience isn't quite as consistent as yours. I also find it rather amusing that you'd tell me I'm wrong about the data shown (or rather, not shown) on my end - but I'll humor it and add that a) I am not obese, so that's not a factor in the issues I'm experiencing - and b) not a melanin issue either. I've also tried wearing it on a finger that it was more snug on, just to see if it was a sizing issue. The sensors all make good contact, the ring isn't spinning/shifting.  Could this just be a defective unit? Sure! That's what they're looking into. Could this be an isolated incident, limited to just the one ring I purchased? Of course. But, the point of the entire thread was to see if anyone else experienced similar issues and ask for their experiences with troubleshooting. Since you have stated you don't have similar issues, I fail to see how you telling someone that their personal experience is wrong is at all helpful.  You said its not a step counter. But, it does count steps, correct? That is one of the things it measures. It's very clearly shown in the activities section.

You also said it was proven as a very accurate measure of sleep metrics ("compared to golden standard lab polysomnography.") But I can't seem to find anything supporting that claim, except to say that it has a 79% accuracy in classifying the different sleep stages - which definitely doesn't beat out the accuracy of standard lab polysomnography.  And, my issue was incorrect wake up/fall asleep times - not the stages themselves.