I'm afraid not. It affects people randomly, just like leaving for good does. I wish I could pin point a rhyme or reason, but there doesn't seem to be.

[Caitlyn has theories, of course. Everything from glitches in the system to it being related to them meeting the Council's demands, but nothing feels like the right answer.]

In most cases, people leave here for a week, but the amount of time passing in their worlds is always different. Vi and I were home for a little over nine months. I've seen some that say they were home for years. Some, as you said, were home only a short time. It's not very consistent.