Azure CDN Adds Pragma: Header Without Cache

I installed Azure CDN using Akamai standard tier. My origin is a web application. I configured the cache control header in my web.config like this:

<clientCache cacheControlMode="UseMaxAge" cacheControlCustom="public" cacheControlMaxAge="30.00:00:00" />

      

        
        
        
      

    

In my markup, I hit my image file with the following code:

<img src="https://xxxx.azureedge.net/Content/Images/Turtle.jpg?v=1.0.0.27987">

      

        
        
        
      

    

When I do this, I get the following response headers:

cache-control:public, max-age=2591903 
content-length:2321435 
content-type:image/jpeg 
date:Mon, 03 Apr 2017 19:34:23 GMT 
etag:"2e7a1f1690a9d21:0" 
last-modified:Thu, 30 Mar 2017 19:59:05 GMT 
pragma:no-cache 
server:Microsoft-IIS/8.0 status:200 vary:Accept-Encoding x-powered-by:ASP.NET

      

        
        
        
      

    

Pay attention to the pragma: no-cache. I have no IDEA where this comes from. It is definitely NOT in my origin to load the cache. If I hit the origin, I see the following headers sent for the same image:

Accept-Ranges:bytes
Cache-Control:public,max-age=2592000
Content-Length:2321435
Content-Type:image/jpeg
Date:Mon, 03 Apr 2017 19:41:50 GMT
ETag:"2e7a1f1690a9d21:0"
Last-Modified:Thu, 30 Mar 2017 19:59:05 GMT
Server:Microsoft-IIS/8.0
X-Powered-By:ASP.NET

      

        
        
        
      

    

This means that when you hit the CDN, instead of showing this image from the http cache, it sends an ETag and I'm wasting HTTP feedback. I am guessing the culprit is the pragma: no-cache header that is being sent, which overrides the cache control header. My questions:

• Why does Azure CDN add this pragma: no-cache header when serving my image?
• Is the pragma: no-cache causing us to see a 304 / ETag check instead of serving the http cache?

Thank!

Edit: I've also tried removing the tag from the web.config. I can still see the ETag passed for the image instead of serving it from the browser's http cache.