Watch OS : NSUrlSession Credential caching

Question

I want to implement "logout and new login" feature from iPhone and Apple Watch.

• I am able to clear the credentials from iPhone (Using NSURLConnection because its old code) after logout, but not able to from apple watch (Using NSURLSession).

• I am using NSURLSession in Apple Watch as it is new and recommended by Apple.

• I tried with ephemeralSessionConfiguration to connect with server from apple watch (Watch OS 2.0, Swift 2.0, iOS 9.0 >> ). I called: 'invalidateAndCancel' and resetWithCompletionHandler APIs to clear the credentials and no change in the behaviour.

• Only one time it is firing the authentication challenge. After that it is always using the credentials which I provided first time. So I am not able to use the new logged in user credentials.

• I tried to get the Credential store and cache to clear the credentials. But the shared credential store and cache is empty.

Question

Is there anything wrong with my approach ? or Is it a bug of Watch OS 2.0 ?