Apple Watch WatchOS 26 Slow Brightness Increase
The first thing that caught my eye after upgrading to WatchOS 26 was the fact then when I raise and turn my wrist my series 10 watch has not changed it's brightness yet. You actually have to wait 1/3-1/2 second to watch it change. I know that's not a lot of time, but in actual use, to see what time its you can find out and put your wrist back down without the watch ever increasing its brightness. Bottom line is that it worked perfectly before the upgrade.
Apple Watch Series 10