Sensor1.get_forces() vs acquire_net_contact_force_tensor()

Hi,
I’m working with a toy example which is based on the cartpole model but without the slider and I want to print the contact forces at the cart.

I see that there are 2 methods to get contact forces: 1) placing a sensor 2) acquire_net_force_tensor(), what is the difference between them?

In my example, I placed a sensor at the bottom of the cart
sensor_pose1 = gymapi.Transform(gymapi.Vec3(0, 0.0, -0.125))
sensor1 = gym.create_force_sensor(env, ball_handle, sensor_pose1)

when printing the values from the sensor and from acquire_net_contact_force_tensor(), the forces do not correspond:

See code here:
cart_pole_sensor.py (6.3 KB)
cartpole_sensor.urdf (1.1 KB)