Analyzed the issue. You were correct that her behaviour is inconsistent.
If EXH < 10 she blows you off when you chat with her about the dancer mission.
Good news is, due to a consecutive error the quest still advances and you can talk to zayla and then again to khelara and can send her dancing nonetheless.
I corrected it in V2.20. She blows you off if EXH is < 10 and you can not ask her about that again until next day. repeatable until your EXH >= 10, then it proceeds.