Question Agent ignores negative reward

I am trying to train an agent to be able to cross the street avoiding hitting cars, in the image below an example.


I set a positive reward for the agent as soon as he manages to cross the street and a negative reward when he hits a car.
The problem is that the agent seems to ignore the negative reward and takes no action to avoid hitting the cars. I would like it to stop going foward (Wait until
car gets out of the way) or to move backwards to dodge a car.

Can anyone help me?

This is part of my code that I think may help to unsderstand how I'm doing it:

Code (CSharp):

1. public override void OnActionReceived(ActionBuffers actionBuffers)
2.     {
3.         Vector3 controlSignal = Vector3.zero;
4.         controlSignal.y = actionBuffers.ContinuousActions[1];
5.         transform.Translate(controlSignal * speed * Time.deltaTime);
6.  
7.         // I call this function when agent crosses the street, I set a positive reward and end the episode
8.         if (transform.position.y > 6.0f)
9.         {
10.             SetReward(1.0f);
11.             EndEpisode();
12.         }
13.     }
14.  
15.     // I call this function when the agent hits a car, I set a negative reward and end the episode
16.     public void finish() {
17.         SetReward(-1.0f);
18.         EndEpisode();
19.     }
20.     }