UPDATE: I found the non-working stairs. They were in the ancient ruins on the Isle of Jahiliyyah. I believe that is all of them, but let me know if you encounter this again. Some of the updated stairs has a strange graphical glitch. This should now be fixed. I am hearing reports that some of the stairs are still not working, but I'm not able to reproduce the problem, I will keep checking, but if anyone knows which area this is happening, that would help to speed up the solution.