https://bugzilla.redhat.com/show_bug.cgi?id=851758
--- Comment #4 from Peng Huang shawn.p.huang@gmail.com --- The order of engines is not fixed. Engines are sorted by recent usage. So when you login, the recent used engine will be active.
That means, in last desktop session, you log out with chewing is active, when you log in again, ibus will enable chewing for you. If you log out with English engine, ibus will enable English engine.
So I think it is not a bug.