My mineral tracker indicates that at the opening of the Vol’Gol Ogre Mound cave in Duskwood that a Tin Vein should spawn near there. It is viable on my mini-map, but after an extensive search around the location I can’t find it. After zooming in close to the location on my map it appears the vein of ore is in the wall making it non intractable but still able to be seen when searching for minerals on the mini-map. I can post an image if this explanation of the bug is not enough.
Years long problem