Almost ANY sudden change in shoe type, especially one where the mechanics are a bit different, such as here where it sounds like you may have gone to a shoe with more sole stiffness, can cause your feet to feel weird and even sore after as little as an hour of walking. This can also happen in old shoes where you put in a very different insole, for example and your feet will continue to feel sore after you take the new shoes off.
The degree of this effect is much less pronounced when switching from one type of running shoe to another than for switching from running shoes to old-style heavyweight boots, but it is there and I have experienced it many times.
If this is what is going on, and not some injury you got, then your feet may just have to adjust to the the new shoes. The general prescription for making the change is to initially only wear the shoes until they become uncomfortable, then switch back to the old shoes until your feet don't feel sore anymore, then try wearing them a bit longer. What usually happens is after a week or so everything is fine with the new shoes, so long at you don't leave them on initially until you have a more long-term soreness that take longer to go away.
Hope this helps a bit.
Of course if the shoe don't stop doing this to your feet – it should happen pretty quickly – then something else may be wrong. I suspect the culprit here is that you put the new shoes on and went for a hike (9 miles straight off, in new shoes, is too much) and that may have over done it on the initial accommodation. Wear them around the house, or put you old shoes in you pack next time. I would not go on a long trip with shoes you are not %100 sure about yet.
The good news is if this is what is going on then it is normal, a will work itself out. Bad news is that 8 days may not be enough to be sure, especially when you push things too far initially.