Did Apple change how they monitored sleep in WatchOS 26?

I have been using my Apple Watch 10 to monitor my sleep since I purchased it in December of last year. When I upgraded it to WatchOS 26, I noticed that the monitoring of my sleep was very different from the results seen in WatchOS 11. In WatchOS 11, the results of my sleep seemed to reflect what I experienced, in that nights when I had disturbed sleep, or when I woke up in the middle of the night, the event was shown in my sleep results. That no longer seems to be the case in WatchOS 26. Now, my sleep results always shows me being awake far more than I recall, meaning that it shows that I got less sleep than my experience says I did. For example, last night, I thought I got a pretty good nights sleep (for me, at least). I recall waking up at about 1 AM, and going back to sleep, and waking up again about 5:30, but going back to sleep until after 7AM, with a short waking period shortly after 6. However, the watch data says I was going between being awake and asleep almost constantly during the night, and that I was awake for well over 2 hours. This does not fit my recollections at all.

Sorry for the long-winded explanation of what I am seeing, but it certainly appears that the algorithm the sleep app uses to distinguish between being asleep and awake has changed in WatchOS 26, and, for me at least, is no long accurate. Is there any way I can modify this?

Thanks in advance.