Stormglas Right / Left inverted Walls can’t be places correctly. They snap only to one side and can’t be turned around, no matter what you do, they don’t fit.
There is an easy fix for this. If you have stairs or a sloped roof you are trying to fill in the side of with those inverted bois, you have to remove the stairs/sloped roof first, place the angled wall, then you can replace the stairs or roof. I know its not the best way but now that you know this you won’t mess up later as often.
That said, I’ve been able to place them more or less correctly if I put up a ceiling and hang them from the underside of that ceiling, as long as there’s no stair, ramp, or sloping roof where the wall piece is going to go. Those can be added later without problem, but if you put them down first, then you’ll have the problem @BradMunkey mentioned.