Got both and WATCH 6 and WATCH Ultra. Recently had an issue with the Ultra not charging and had it in for repair. Through research here and there found out my WATCH 6's battery health was at 83%.
Did select Settings > Battery >Battery Health > Optimized Battery Charging to mitigate the issue on both WATCH's.
Did select Settings > Battery >Battery Health > Optimized Battery Charging to mitigate the issue on both WATCH's.