Scene change breaks Scrollview (buttons added via script)

The video below describes the problem I'm facing. Everything works great...until it doesn't.

PaintGM script:
void Start ()
{
DrawColor = new Color(1f, 1f, 1f);
PaintGM.ToolType = "Pencil";
PaintGM.ICanDrawNow = true;

for (int i = 0; i < NumberOfPencils; i++)
{
GameObject thisPencil = Instantiate<GameObject>(basePencil);
thisPencil.transform.SetParent(PencilPanel.transform);
thisPencil.GetComponent<Pencil>().PencilColor = GetNextColor(i);
thisPencil.GetComponent<Image>().color = GetNextColor(i);
}

GameObject thisEraser = Instantiate(baseEraser);
thisEraser.transform.SetParent(PencilPanel.transform);
}

PencilPanel is the content panel inside of the scrollview.
basePencil and baseEraser point to the prefab UI Buttons shown at the beginning of the video.
basePencil and baseEraser both have LayoutElements in them, both using no customized layout settings (no checkboxes are checked).

Thanks in advance,
Mark