As far as I can tell, time isn't linear here. This place takes people from wherever it chooses if it has any sentience at all.

[ She's still debating that particular detail, but that's not something that Barriss would care to talk about so she moves on. Looking past her, Ahsoka searches for the thing she'd been following before running into an old - she hasn't made up her mind there either - acquaintance. Her thoughts pause on the demon search for now to reply to her inquiry. ]

I've spoken to Master Kenobi. I've had a few days to acquaint myself with the people here. They all give the same story when it comes to the dream aspect.

I'm still looking for an alternative explanation.