URLSession and URLCache not working as expected

For a GET request which is consistently the same, I'm returning in the response this response header.

Cache-Control: max-age=3600, private

I'm creating a URLSession with this configuration. Basically, ensuring my cache is large. The URLSession persists throughout the life of the app and all requests go through it.

 var configuration = URLSessionConfiguration.default  
        let cache = URLCache(memoryCapacity: 500_000_000,
                               diskCapacity: 1_000_000_000)
        configuration.urlCache = cache
        configuration.requestCachePolicy = .useProtocolCachePolicy

I create a data task with the completion handler:

let task = session.dataTask(with: request) { data, response, error in

//... my response handling code here
}
task.resume()

There isn't anything complicated or unusual I'm doing. I've used this code for years, and I'm now trying to optimise some calls with a caching policy.

So I have 2 issues:

1. Requests that have no-cache policy are still being saved into the URLCache. Which I've confirmed by looking into URLCache.shared.cachedResponse . Why is it caching them when the response explicitly states no-cache policy and I've told the session to use the protocol policy.

2. On the request where I do want to use the cache, when I call session.dataTask on subsequent times, it never fetches from the cache. It always hits the server again - which I can confirm from the server logs.

What piece of this am I missing here?