Timelines will stop running after you change rooms. It might persist if you have the object set to persistent, but I'm not sure.
If there will be no object animation, you can just show images of each room rather than actually changing rooms. Or, like I said, try setting the object to Persistent. I don't know if the timeline resets when you change rooms, so watch that in the Debug Mode.
Also, make sure you set timeline_speed to greater than 0, otherwise the timeline won't execute.
Ah, I fixed it by duplicating the orb and having it do the rest of the timeline in the create event - so there's sort of a separate timeline per room, thank you though