Trying to implement proportional navigation into Unity using C#

I tried using the equation for proportional navigation found in this wiki article but when I attempted to implement it in game, the missile often goes off in some direction opposite of my target.

I am not sure if this has to do with the way I normalized the acceleration to give it a maximum velocity, the precision of the coordinates, or my calculations but I have not been able to find the root of the issue.

If anyone could help it would be greatly appreciated.

Here is my code

public class Missile : MonoBehaviour
{

    Target target;
    public Transform targetTransform;
    public float speed = 5;
    public float propCon = 3;
    Vector3 lastPos;
    Vector3 miLastPos;
    Vector3 velocity;

    void Start()
    {
        target = FindObjectOfType<Target>();
       lastPos = targetTransform.position; 
       miLastPos = transform.position;
    }

    void Update()
    {
        Vector3 targetVelocity = (targetTransform.position - lastPos) / Time.deltaTime;
        Vector3 miVelocity = (transform.position - miLastPos) / Time.deltaTime;
       
        lastPos = targetTransform.position;
        miLastPos = transform.position;

        Vector3 range = targetTransform.position - transform.position;
        Vector3 relVelocity = targetVelocity - miVelocity;
        Vector3 rotVector = Vector3.Cross(range, relVelocity) / Vector3.Dot(range, range);
        Vector3 accNormal = propCon * Vector3.Cross(relVelocity, rotVector);
        Vector3 directionToTarget = accNormal.normalized;

        float distanceToTarget = range.magnitude;

        print ($"TV is: {targetVelocity} and lastPos {lastPos}\nmiVelocity is: {miVelocity} miPosition is: {miLastPos}");
        print ($"rotVector: {rotVector} and accNormal: {accNormal}\nrange: {range} and relVelocity: {relVelocity}");
        print ($"cross: {Vector3.Cross(range, relVelocity)} and dot: {Vector3.Dot(range, range)}");


        if (velocity.magnitude < speed)
        {
            velocity += (speed/10*directionToTarget);
        }

        if (distanceToTarget > 0.1f)
        {
            transform.Translate (velocity*Time.deltaTime);
        }
    }
}