Assignment of float is incorrectly set to zero.

I am have an issue with a camera set up of mine thats designed to prevent the camera from penetrating blocks, in C#. It does this by raycasting to the four points of the near clipping plane of the camera. If one of these raycasts hit, it moves the camera inward. I have managed to trace the problem down to the incorrect assignment of a float.

     public Vector3 cameraOffset = new Vector3();
     public GameObject viewCamera;
     public float clipSize = .4f;
     public float sensitivity = 15F;
     public float minimum = -60F;
     public float maximum = 60F;
     float rotationY = 0F;
 
 
     void FixedUpdate ()
     {
 
         rotationY += Input.GetAxis("Mouse Y") * sensitivity;
         rotationY = Mathf.Clamp(rotationY, minimum, maximum);
         transform.localEulerAngles = new Vector3(-rotationY, transform.localEulerAngles.y, 0);
         
 
         Vector3 realDir = transform.TransformDirection(cameraOffset);
         Vector3 hClipOffset = transform.TransformDirection(new Vector3(clipSize, 0f, 0f)); // Setup Raycasts
         Vector3 vClipOffset = transform.TransformDirection(new Vector3(0f, clipSize/2f, 0f));
         
         
         RaycastHit urHit; // Raycast info holders
         RaycastHit ulHit;
         RaycastHit lrHit;
         RaycastHit llHit;
         float modifyDist = 1f;
         
         Vector3 urDir = realDir + vClipOffset + hClipOffset; // Specify the directions to the four corners of the cameras near clipping plane
         Vector3 ulDir = realDir + vClipOffset - hClipOffset;
         Vector3 lrDir = realDir - vClipOffset + hClipOffset;
         Vector3 llDir = realDir - vClipOffset - hClipOffset;
         if (Physics.Raycast(transform.position, urDir, out urHit, urDir.magnitude)) { // check if it clips upper right edge
             float a = urHit.distance / urDir.magnitude; //prevent penetration by pushing camera in
             if (a < modifyDist) modifyDist = a;// always use the closest collision
         }
         if (Physics.Raycast(transform.position, ulDir, out ulHit, ulDir.magnitude)) { // check if it clips upper left edge
             float a = ulHit.distance / ulDir.magnitude; //prevent penetration by pushing camera in
             if (a < modifyDist) modifyDist = a;// always use the closest collision
         }
         if (Physics.Raycast(transform.position, lrDir, out lrHit, lrDir.magnitude)) { // check if it clips lower right edge
             float a = lrHit.distance / lrDir.magnitude; //prevent penetration by pushing camera in
             if (a < modifyDist) modifyDist = a;// always use the closest collision
         }
         if (Physics.Raycast(transform.position, llDir, out llHit, llDir.magnitude)) { // check if it clips lower left edge    
             float a = llHit.distance / llDir.magnitude; //prevent penetration by pushing camera in
             if (a < modifyDist) modifyDist = a;// always use the closest collision
         }
         
         Debug.DrawRay(transform.position, urDir, Color.green); // ur debug draw rays
         Debug.DrawRay(transform.position, ulDir, Color.red); // ul
         Debug.DrawRay(transform.position, lrDir, Color.cyan); // lr
         Debug.DrawRay(transform.position, llDir, Color.yellow); // ll
         
         
         
         viewCamera.transform.localPosition = cameraOffset * modifyDist; // modify the normal vector
         
             
         
         viewCamera.transform.LookAt(transform.position); // always look at this transform
     }

Using Debug code not shown here, i have traced the problem to this section of code.

                 float a = llHit.distance / llDir.magnitude;
                 if (a < modifyDist) modifyDist = a;

The value modifyDist seems to get assigned to 0 (modifyDist is a float), even thought the value of a is not zero. This is the only code in the script, so the problem must occur here.

The issue only happens on the two left side raycasts, with the right side working properly. The only difference between the two sides is the hClipOffset beings subtracted instead of added.

The small section of code right above returns valid numbers, but the assignation fails, for example this was debug logged directly after the if statement: llHit.distance = 7.5116 llDir.magnitude = 10.15666 a = .73263 modifyDist = 0

I have no idea why modifyDist is being set equal to zero, or why it is only happening on the left side. Any help will be appreciated.