Hi QuinnyLi good question, since setting the TTL to '0' is setting it to never expire, I would have thought the trait data would remain unchanged but I'd like to clarify a couple of things if that's ok:
1 - When you are talking about real-time population, are you talking about the corresponding segment? Just want to make sure where you are seeing this as the traits have Unique Trait Realisations, what exactly shows 0 population?
2 - Have you changed anything to the trait expression.
Feel free to send me a Private Message with the trait ID, I should be able to look it up