Theres a bug on Carapace of N’Zoth in which if you activate the cloak at the same time the boss changes to phase 2, the cloak takes you to the second room instead of the entrance where Wrathion is.
Happened to me once, don’t really know if that’s supposed to be the case, but if not I guess this belongs here.
Edit: this is on the myth fight.
Does Wrathion still restore sanity on the phase transition on mythic? I am aware that he doesn’t actually come into the phase 2 room after the transition on mythic. But he should still do the sanity restoration at the transition since he opens up the “door” for you.
Also you should post a bug report in the bug forums. It is why they are there.