Question about different performance

Hi, I am using this repository now and also learning the source code, but I have a question.

I used the "python mujoco_mpc/demos/agent/cartpole_gui.py", and the Shadow task looks really good. But when I ran the "mujoco_mpc-main\python\mujoco_mpc\demos\predictive_sampling\particle.py" code, it almost doesn't work. Is this because in this demo, we don't sample enough to find the good actions? Normally, how many iterations it needs and can the Horizon be set longer like 1s?

Really appreciate your response in advance!