im trying to add this behavior in your example file add_remove_series.dart:

...
zoomPanBehavior: ZoomPanBehavior(
        enablePinching: true,
        zoomMode: ZoomMode.x,
        enablePanning: true
    ),
...

after adding or removing line series, zoom of lines stops working
.. update...
it also stop working when we dont add or delete anything and start-stop zooming