Unable to Override Cache Control response headers in ASP.net Web API using OwinMiddleware for signalr/negotiate signalr/start calls

I have the following code:

 public class cacheMiddleware: OwinMiddleware
    {
        public cacheMiddleware(OwinMiddleware next) : base(next)
        {
        }


    public override async Task Invoke(IOwinContext context)
    {
        context.Response.Headers["Cache-Control"] = "no-cache, no-store, must-revalidate";
        context.Response.Headers["Pragma"] = "no-cache";
        context.Response.Headers["Expires"] = "0";
        context.Response.Headers.Set("Strict-Transport-Security", "max-age=31536000; 
                                     includeSubDomains;");
        await Next.Invoke(context);
    }
}

Which is supposed to have changed the Http cache control headers to have "no store, no-cache, must-revalidate", but when I check it in Chrome Dev tools, I always get no-cache. I get the following values in response header for SignalR calls - signalr/negotiate & signalr/start. Interestingly signalr/connect? & my other calls are working working fine as expected. Is there anything more to do for signalr/negotiate & signalr/start calls?

signalr/negotiate & signalr/start:

Cache-Control:no-cache
Connection:keep-alive
Host:10.0.211.202
Pragma:no-cache
Expires:-1
Strict-Transport-Security:max-age=31536000; includeSubDomains;

signalr/connect:

Cache-Control:no-cache, no-store, must-revalidate
Connection:Upgrade
Strict-Transport-Security:max-age=31536000; includeSubDomains;
Upgrade:websocket

I tried possible solutions from net but no luck. Referred Setting Owin Cache Control headers in ASP.net Web API & signalr doesnt allow cross origin requests &

Is there a reason I'm not able to change what's in cache-control from no-cache to no-cache, no-store?