Lerping multiple gameobjects precisely

For a project I need to continously lerp bars from left to right.

Each bar has a script on it, that lerps it to the right. When the bar hits the right border, it gets set to left border and start again to lerp from left to the right. The lerping works fine.

 void FixedUpdate()
     {
         if (BarSetting.Instance.Running)
         {
             //bar has reached the next position
             if (Vector3.Distance(transform.position, nextPosition) <= 0)
             {
                 //when the bar has reached set the next position
                 startPosition = movementType.getFirst();
                 transform.position = startPosition;
                 nextPosition = movementType.getLast();
 
                 //reset the timer for the lerp transition
                 float distanceBetweenStartAndNext = Vector3.Distance(startPosition, nextPosition);
 
                 timeToReachNextPosition = Utilities.CircumferenceInUnits(BarSetting.Instance.Speed) * distanceBetweenStartAndNext;
                 timePassed = 0;
             }
             else
             {
                 //move the bar closer to the next position
                 timePassed += Time.deltaTime / timeToReachNextPosition;
                 this.transform.position = Vector3.Lerp(startPosition, nextPosition, timePassed);
             }
         }
     }

The problem is that the space between the bars doesn't stay exact the same. With just a few bars it works fine, but I need to lerp like 30 bars and there the space varies a lot.

I dont think, that the problem lies with the lerping itself. It seems, that Unity has problems with handling multiple lerping exactly.

Startposition of all bars:

How they end up after a few rounds

Has somebody an idea for a fix or an alternative solution?

Thanks in advance.