I've never had any trouble with it on my series 9 (purchased Dec 2023 just before the feature was disabled). It's always closely matched the fingertip meter tha

I've never had any trouble with it on my series 9 (purchased Dec 2023 just before the feature was disabled). It's always closely matched the fingertip meter that I have. Which is to say they both always read >= 95% for the most part.