Sleep score has changed for the worse since iOS upgrade

I've had a similar trend in my sleep tracking since the upgrade to 26.2, my sleep tracking has devolved to "No Data" since the upgrade. I've upgraded, rebooted, unpaired, re-paired, still "No Data". I've talked with tech (can't remember what level) before recently, and she had no answers to the "No Data" problem. It's possible that my sleep has actually deteriorated to the point of "No Data", but wouldn't the watch track a low score...even "0" rather than "No Data "? "No Data" implies to me that the watch is not tracking. What do you think?

My REM sleep does not appear remarkably different from before, and I have never seen the "no data" report.

This leads me to believe there is some OTHER factor in play than the version of iOS or watch OS.

I think part of the problem is that more people struggle with their sleep than Apple seems to be aware of, and the fact that they would tinker with people's health by rolling out an imperfect sleep tracker is insensitive to say the least. Many, myself included, perhaps rely on sleep scores more than we should, especially if they prove to be...unreliable.

Did you also update WatchOS to 26.2?

I find watch upgrades difficult because it requires the Watch be on the charger and charged at least 40 percent AND the phone be nearby the whole time.

I wear an Apple Watch series 10 (GPS) 46 mm on my left wrist.

I do have a sleep focus set for 10PM to 9 AM daily.

No issues.

I updated the iphone prior to updating the watch. My watch is never at 40% battery level unless I am using it in a sports event.