It turns out that this behaviour is not an issue with our library, the same behaviour is experienced with vanilla AFNetworking.

It possible relates to the keychain broken issue on the iOS 6 simulator when doing 'live' switching to perform the tests. Have opened issues on AFNetworking and Apple

AFNetworking:
https://github.com/AFNetworking/AFNetworking/issues/1598

Apple:
https://devforums.apple.com/message/919209 (needs Apple dev account to access)

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