Solve Twilio WhatsApp Verification

I already use a Twilio number for live API traffic on my website and Twilio confirms the line “supports WhatsApp Business.” SMS messages flow and the logs look clean, yet the Android WhatsApp Business app never receives a verification code when I try to link the same number... (Budget: $10 - $30 USD, Jobs: Android, API, Compliance, Mobile App Development, PHP, Technical Support, Testing / QA, Twilio)