Sometimes you do not reply. Why?

Two likely reasons.

1. The messaging rules. WhatsApp only lets a business message you freely for a period after your last message. Outside it, our message may not be delivered. If we cannot reach you there, we may send an SMS. Sending us any message re-opens the window.
2. The assistant is unavailable or you have hit the daily chat limit. The menu and the exact commands still work — “my deals”, “my balance”, “send 5000 to @handle”, “MENU”.