HTTP Cache on mobile

In the process of porting an application built upon on a REST API, I have observed that HTTP requests sent from the Adobe AIR runtime do not seem to honour caching features like ETag or Last-Modified.

I used the URL of a file hosted on a CDN ; the response headers definitely contain directives that should then provoke conditionals requests from the client.

However, using Charles Proxy, I have noticed that the subsquent requests are never sent with headers like ETag or If-Modified-Since. Therefore, the server responds with 200 OK (not 304 Not Modified) and the request body is sent again. I had the same results on Android and iOS.

Is this feature really is unsupported or is it a bug ? (I haven't found a lot of information online except similar issues on Mac).

Since our REST API is relying on HTTP standards, I am about to implement some of this caching mechanisms manually - even though I believe software developers using AIR should not have to do this.

Note: the same requests are correctly cache when running in the browser

I can provide an example file / code but I would like to have some info from Adobe about this.