META has confirmed that the issue has been resolved, as updated on their status page: https://metastatus.com/whatsapp-business-api.
Update · UTC
The Meta Engineering team has identified the root cause of the issue and is diligently working towards a solution.
We will provide another update as soon as additional information is available from Meta.
Investigating · UTC
We are aware of an issue that impacts the sending of carousel templates.
The error message is:
"Carousel template messages require interactive template to be enabled."
We are monitoring the situation closely and awaiting Meta's response.
Meta status page: https://metastatus.com/whatsapp-business-api