Content-Type Charset in Lowercase When Deployed to Azure App Service

Question

I am experiencing an issue with my API deployed to Azure App Service. Locally, my API correctly returns the Content-Type header as application/json; charset=UTF-8, but when deployed to Azure, the header is returned as application/json; charset=utf-8.

Here are the specifics:

• Local Environment: The API returns Content-Type: application/json; charset=UTF-8.
• Azure App Service: The API returns Content-Type: application/json; charset=utf-8.

Questions:

1. Are there any environment-specific settings or App Service backend that could be altering the header value?
2. How can I ensure the Content-Type charset is consistently returned as UTF-8 rather than utf-8 in Azure App Service? (Without using APIM)

Any insights or recommendations would be greatly appreciated.

Local:

App Service: