Drag prefab on grid

I am trying to drag a prefab(wall) from my project folder into my scene on a grid, but it's not working.
I would also like to drag multiple different prefabs on the grid after each other.
I read earlier posts about this, but they were all scripting grid issues, while mine is more a unity tool problem.

With a png it does work IF I select the grid in the hierarchy, but after I drag the png on the grid, the png object is selected and the grid deselects, if I then try to drag a new png on the grid it does not place on the grid, since the grid is not selected anymore.