When using the ListBox control with drag & drop enabled, the "drag" event seems to be working correctly (ex. item is highlighted, it gets "selected" and "moves" as you move your cursor) but the "drop" event more often than not doesn't add the item to the list it was dragged to. Through testing, I've noticed that it does appear to occasionally get added to the other list successfully, but only after several failed attempts and it seems to be pretty random.
I've created two examples in REPL based on demo code:
In our real application, these ListBox components are bound to properties of the View's model, which results in code that essentially uses "local data" similar to the examples above. I've noticed that the "official demo" of the ListBox component's drag & drop feature (https://demos.telerik.com/aspnet-core/listbox/drag-and-drop) appears to work correctly. However, I've also noticed that this demo is using an Ajax data source, which I suspect might be what's causing the different behavior.