drawn labels don't get destroyed

[janedoesrepo]

Hi, I use your DrawBoundingBoxes.cs but the boxes (or rather the text) don't get destroyed properly:

After receiving the boxes from the parser I use the following code:

if (this.boxes.Count > 0)
{
    boundingBoxDrawer.DrawBoxes(this.boxes);
}
else
{
    this.boxes.Add(new EmptyBox());
    boundingBoxDrawer.DrawBoxes(this.boxes);
}

Any ideas what's happening??

Update: The problem seems to occure as soon as more than one object is detected in a frame. It detected two objects. Both boxes got destroyed at the next update but one label remained in the view.