Ok,
all of that looks fine so far.
Can you show what is inside your list in the widget tree ?
And the list widget properties, to see the binding of the aggregate result.
Also can you show the aggregate details of how you retrieve data.
And any CSS in your module or screen that could explain.
When you look at it with table or pc size, does it look all right then ?
How many items are in your list ? What happens if you limit items returned from aggregate to an odd and/or an even number.