UI panel disappears after I instantiate objects

Hi!

I am trying to write code which creates a dynamic UI table in Unity. I started with a code that instantiates a new UI "row".

Unfortunately it doesn't work. Each time that the prefab gets instantiated, the whole content of the Panel becomes invisible, even the text that was there already before!.

Why could that happen?

Code (CSharp):

1.     void Start()
2.     {
3.         var newRow = Instantiate(rowPrefab);
4.         newRow.transform.SetParent(verticalList.transform);
5.         //DrawTable();
6.     }

Best,
Aleks