Chartjs is watching for parent node to understand resize. But when you use libraries like Gridstack / Gridster etc., these libraries have different div layouts. So instead of parent node, Chartjs should monitor Gridstack Item node to understand resizing better.
We can put an option into chart options. If user specify an div id, instead of parent node of canvas, we can monitor specific DIV. In that case, when user resize the Gridstack widget, Chartjs can automatically resize itself for the new grid height and width.