Testing numbers simulate the integration. They do not connect a real WhatsApp account or deliver messages to real recipients. A simulated success is useful for checking your application flow, but it is not proof of live delivery.
Confirm the number type and selected project before investigating a delivery failure. Use a properly connected real number for a real-recipient test, subject to its access and funding requirements. If you believe a number was created with the wrong type, ask support about its displayed state rather than trying to pair a testing number with a real phone.