1, try to connect with your mobile phone, otherwise you will lack GPS positioning and the movement distance data will be inaccurate.
2. My Watch > General > Wrist Detection must be turned on (default).
3. my watch > in terms of health, the data of birthday, gender, height and weight should be accurate.
4. My Watch > General > During exercise and fitness, the heart rate and fitness tracking functions should be turned on.
5. my watch > during fitness activities, all switches should be fully opened as much as possible.
Most likely, the reason why health activities do not turn is that the above settings 2, 4 and 5 are partially or completely turned off.