I have 2 connected sortable lists. One is inside an accordion. When I try to drag items from the sortable in the accordion, the helper disappears as soon as I get outside of t
In your sortable call you want to use the following options:
helper: "clone",
appendTo: "body", // or whatever element you want the helper clone to be attached to
This does two things. First it makes a copy of the element being dragged (helper option), second it attaches that helper to the specified element (appendTo option).
Similar question here: jQuery-Ui: Cannot drag object outside of an accordion