How to set a useful initial state?

[fengDd11]

When I use python to verify the generated library, I find that if my initial state X_0 is set to all 0s, the solution will fail and always output 0. However, if I give a value, such as 0.1, it will work normally. In actual applications, do I really need to give a very small initial value, or is there something wrong with my problem construction? examples/cartpole_example_mpc.py when i use the exeample and set x0 = np.array([0.0, 0, 0, 0]),the same problem occurred.So，How can i set the initial state correctly.