Everything says "Connected" but no customer is getting messages — where do I even start?

Settings → WhatsApp → Message history, filter Status = failed, and read the red line under the newest rows: it names the real reason in plain words. If those rows say "paused" rather than "failed", sending was switched off platform-wide and an amber bar on your Orders board is waiting for you to press "Send these now" or "Discard". No rows at all for a recent order? Check the order actually reached your board first.