Change Exercise ring on Apple watch

Hello, needed some help, I have a series 5 Apple Watch, and the exercise ring is currently set at 60min, and wanting it lowered to 30min I’ve tried the steps on apples web site to change it, but nothing has been successful, does anyone have any tips on how to change it? other relatives have there’s set to 30min, mine seems to be the only one set to 60min.