For what it's worth, the plant is attenuata and not fasciata, not that the difference is particularly big. If it has tubercles on the upper surface of the leaves (maybe only some leaves not all) then it is not fasciata. So at least there's a reliable straightforward way to tell the two species apart most of the time.
My attenuatas go brown with drought stress/root loss and they go brown when given sharp increases in light (like we are having at this time of year). Those changes are reversible (up to a point, I suppose), and we have neither heat nor cold to complicate things, so your experience may be different.
My fasciata (acquired at a bargain price and it is the real deal) is a bit of a cranky plant, but it has been slowly getting bigger. I will try to get some decent close up pictures when it becomes more presentable.
