Bar chart with straight line

Hello Everyone,

I want to create a bar Chart with line. PFA screenshot (Bild1).

The line moves rightward based on the month selection.

I was able to acheive this Feature using data binding for left margin for the line.

However have the below issue and need your Inputs:

The Chart is placed in the grid layout and in the Chart properties the width and height is set to Auto, so that the Chart gets adjusted based on the Screen size.

Because of this the line is not displayed correctly when the Screen size changes. PFA screenshot (Bild2).

Please let me know for your suggestions.

Thanks.