Well, as you saw in the dumper, your hash contains ARRAY(0x1a56440) and only ARRAY(0x1a56440). That's the stringification of the address of your array. (Which also points to where the problem is happening.)

You then push all the elements of your list unless the element is 'ARRAY(0x1a56440)'. Which is all the elements.

When you push all the elements on, of course your arrays will have the same contents. :)

Check how you're passing those arrays in, and make sure you dereference the arrayrefs getting passed in, to avoid assigning a single value (the arrayref) into a new array of one element.