We are using message Templates for sending WhatsApp messages and have been facing issue recently with delivery of Messages sent with WhatsApp API. Its working fine for some old templates but not delivering for newly active templates. WhatsApp account is showing zero issue.

API used is :"https://graph.facebook.com/v14.0/<whatsapp_mobile_id>/messages"

What could be the issue? Anyone facing the same issue ? Kindly throw some light.