It's RNG event, so you should try to re-enter again to reset RNG.
If I remember correctly, the newest event during Visiting Barrack is trigger by RNG during the late night (before 6.00 AM) you also need to do Alden quest to trigger it as a requirement. If you already done it all. The last you have to do is "do it again" since it's also RNG. You can just revisit it again or save-load until you get some.