It should be because you set the access right of WeChat to fitness exercise as forbidden (as shown in the figure below), so the steps of WeChat exercise do not match the actual steps.

The solution is simple, just click Allow, and then I will teach you how to set it in the form of screenshots, hoping to solve your problem.

The specific steps are as follows: (Mobile phone brand demonstration: Huawei)

1, let's open the settings on the desktop first.

2. After entering the settings, click Apply.

3. Click Permission Management in the application interface.

4. Enter the rights management interface, slide down and click on WeChat application.

5. Then click on the fitness exercise under the ban.

6. Finally, click Allow to open the permission.