Debug Twilio n8n Messaging

My n8n instance drives customer outreach through Twilio for both WhatsApp and SMS. After I recently updated message templates, rotated API credentials, and rearranged several workflow steps, everything went sideways: WhatsApp messages never leave the workflow, and SMS reaches clients without the subscription code variable that should be injected.

I need the current workflows reviewed end-to-end, the root causes isolated, and the issues fully resolved. A solid grasp of Twilio’s Messaging/Conversations APIs (WhatsApp & SMS) and hands-on n8n debugging is essential, along with clear communication so I understand exactly what went wrong and how to prevent a repeat.

Deliverables
• Repair the existing n8n workflows so both WhatsApp and SMS messages are sent successfully, with the correct subscription code included.
• Document the fixes: line-by-line or node-by-node explanation of each change, plus any template or credential corrections.
• Share best-practice notes for Twilio message templates, variable handling, and version control in n8n to avoid similar mishaps.

Please include a brief summary of comparable Twilio + n8n projects you’ve completed, your hourly rate or a fixed-price estimate for this troubleshooting round, and your earliest available start time. A successful collaboration here can lead to steady follow-on automation work.
P.S this job is only for US and European based freelancer and I have to have a face to face meeting on zoom or another method allowed by freelancer in order to move forward with the job.