How to change cursor when onMove returns false

[hobbeschild]

I have a Sortable with an onMove method that returns false in some circumstances. How can I change the cursor to "not-allowed" when it returns false, so it is clear to the user that they are not allowed to drop the item there. This is what I have tried...

https://codepen.io/hobbeschild/pen/wBMoqLL

I can find lots of answers explaining how to change the cursor when dragging, but they are permanent CSS solutions, not dynamic according to the onMove event.