Y-Axis Crosshairs don't snap to center of marker?

[vicatcu]

I'm making a simple time series line chart. When I enable x and y crosshairs, the xaxis crosshairs snap to the center of the associated marker, but it seems to me that the yaxis crosshairs (i.e. the horizontal line) doesn't snap to the center of the associated marker and can move up and down if I move the mouse around inside the 'inflated' marker. Is there a setting (or technique) that will prevent that 'play' in the yaxis crosshair?

[vicatcu]

Here is a Codepen supporting my question: https://codepen.io/vicatcu/pen/OJxOXEN