Getting Error on setting selectedStep in train component

Summary:

Hi All,

I have implemented train component in a dialog using cook book as reference. Its working fine. I am trying to enhance this little bit but getting error. Below is my use case.

1 - User has 4 steps in train component. In each step user does some action. I am capturing the steps in database as a reference. Lets say user completed step 2 and closed the train component. I save this step in my DB.

2 - Now I have a button in my table component which allows user to pick up from where they left.

3 - Expectation is once user clicks on the button to resume work, I should launch the train component in the dialog with the step from where left last time.