Legend draws the entries based on the series order in the settings. The columns are drawn also in that order where the first entry is the closest to zero. The info popup however prints them in the reverse order - that is done so that they visually match the more common scenario - multiple columns, all positive (for the negative values the order in the info popup however will not be reversed once more).
Currently what you can do is to use info.advanced.contentsFunction
to render the info popup the way you want.