Looks like a daily rotation yes. I haven't really been keeping track but I think they were (in order) : Gofannon, Izanami, Bergusia, and today (Oct 12th) Volundar. So tomorrow (Oct 13th, after reset) should be Gofannon again, which is the broken one. It freezes up the whole game at the boss fight. Unless they've fixed it. Hasn't seemed to be an issue with the others.