There is also an issue caused by 4.11 which is very noticeable when you drag the container window.
If you then try to loot another container it will just show the old container and you can’t interact with it.
Please vote for this issue here as it is the cause of the bug:
All the other widgets still seem to drag and drop fine, so again hopefully this is fixed in 4.14.
For now you can disable the drag and drop on the container widget easily by unhooking the Detect drag if Pressed in the Container widgets On Mouse Button Down function.
This bug does not effect the actual Inventory System’s drag and drop for items.
I will consider updating the widget drag and drop logic if Epic still hasn’t fixed this bug after 4.14 is released.
Please don’t forget to vote for the issues and hopefully they start fixing some of these UMG bugs soon.