3D Bot tracking glitch

[MoMachine64]

I have 2 3D rigidbody robots(aka cubes) with box colliders in my scene. Here is my script on one of them to follow the other (without rotation) and push it:

public class BotFollowSwerve : MonoBehaviour
{
    public Transform target;
    public float force = 10f;

    private Rigidbody rb;

    void Start()
    {
        rb = GetComponent<Rigidbody>();
    }

    void FixedUpdate()
    {
        Vector3 targetDirection = (target.position - transform.position).normalized;

        rb.AddForce(targetDirection * force, ForceMode.Force);
    }
}

The other robot is controlled by me (the player) and can rotate and move in the x and z axis. The issue is when i face the robot away from the follower robot, the follower just lines itself up about 2 robot lengths away with the player robot and starts vibrating in place. If i move the player robot without rotating it - the follower follows with it, but keeping its distance.

[ArachnidAnimal]

You might have something else going on in your code. The code you posted doesn’t show anything regarding the lead robots rotation.
Maybe the target position assigned to the following robot is wrong, so when you rotate the lead bot, the target position is changing.

As for the vibration, using AddForce might be causing the following robot to overshoot the target, so it has to move the opposite direction back towards the target, then overshoots it again, creating an oscillation effect. Maybe you can avoid applying force on the follower if is close to the target.

var dist = Vector3.Distance(target.position, rb.position);
if (dist > 1.0f) {
   Vector3 targetDirection = (target.position - rb.position).normalized;
   rb.AddForce (targetDirection * force, ForceMode.Force);			
}

Also, increasing the rigidBody drag might help this issue.