WatchOS 10 and battery drain during fitness.

I have a problem with WatchOS 10 on Apple Watch Series 8 with the battery and it's serious. Initially, I thought that Gentler Streak had not been properly optimized yet, and the watch had 70% when I went out on the bike, but after 20 minutes of riding it turned off, and when I turned it on it showed 10%. Today the same problem appeared in the system's Fitness app while running. I was going at 57% and after about 20 minutes (I knew my pace and distance) I realized the watch was dead. Interestingly, in both the first and second cases, the watch turned on, and after introducing energy saving, it behaved as if it had 50%, because these 10% did not go away for anything in the world, and in addition, I turned on the cellular network and Wi-Fi -Fi.

I will only add that such a story has never happened at Nike Run Club.