If I drag&drop a content to another content into a grid and if the two contents are too closed in the result grid, I get a forbidden icon on a part of the element.
I attach a screenshot with an example and the forbidden zone is override in yellow.
You can reproduce this bug in a basket or a search for example.
Note : In a basket, if try the drag&drop from the second element of the grid to the first one, I always have the forbidden icon.