C# while within foreach doesn't complete

Hi,

I'm iterating through objects within a sphere (Physics.OverlapSphere). There are two types of objects found (parent and child). If a parent is found a while loop is triggered to find the distance to it's child objects. These distances needs to be concatenated into a string. (for network optimization). The problem is that the values are not concetenated but spit out separately.

Expected Debug.Log() output:

/ 0 / 50 / 1 / 48.5 / 2 / 11 / 3 / 15

Result

/ 0 / 50

/ 1 / 48.5

/ 2 / 11

/ 3 / 15

I already placed the while loop in a coroutine, but with no result. I stripped the code down to a bare minimum. I'd appreciate a fresh look on this!

 using UnityEngine;
 using System.Collections;
 
 public class tester : MonoBehaviour {
 
     private float radius = 100.0F;
     private int nrOfObects = 5;
     private int objectCounter = 0;
 
     public void FixedUpdate() {
 
         foreach (Collider collider in Physics.OverlapSphere(transform.position, radius)) {
 
             StartCoroutine( combineValues( collider ) );
         }
     }
 
     IEnumerator combineValues( Collider collider ){
 
         string combinedValues = "";
 
         while (objectCounter < nrOfObects) {
 
             if (collider.name == this.name + "_child_" + objectCounter) {
 
                 float distance = Vector3.Distance(transform.position, collider.transform.position);
             
                 combinedValues += " / "+objectCounter.ToString()+" / "+distance.ToString();
 
                 objectCounter++;
             }
         }
 
         Debug.Log (combinedValues);
         yield return null;
     }
 }