I wanted to re-arange a newly added widget to my dashboard and I noticed the position doesn't get saved. I fired up the console and when dropping the widget after dragging, I see the following error coming up:

TypeError: $widget.dashboardWidget is not a function index.php:3136:9

Line 3136:

$widget.dashboardWidget('reload',false,true);}

I figured this would be the cause. Running version 3.11.0.