im not sure if its a bug, bcs it was like that a long time ago, but the thing is that those items are not show bcs there are no mobs with that item lvl, in your case 10th lvl items are not shown in mw bcs there are no 10 lvl mobs in mw. its same in all maps, for example, if you search 40 lvl item in mm, which drop from 45-49 lvl mobs, it wont be shown on map where to go to get them