When the NXOAuth2Client is created in NXOAuth2AccountStore and passed to initAccountWithOAuthClient of NXOAuth2Account, the delegate wasn't reassigned to the account because oauthClient is nil when initAccountWithAccessToken is called.
On a side note, I believe oauthClient.delegate = self; in initAccountWithAccessToken could be removed, as oauthClient will always be nil since the object was just allocated.
When the NXOAuth2Client is created in NXOAuth2AccountStore and passed to initAccountWithOAuthClient of NXOAuth2Account, the delegate wasn't reassigned to the account because oauthClient is nil when initAccountWithAccessToken is called.
On a side note, I believe
oauthClient.delegate = self;ininitAccountWithAccessTokencould be removed, asoauthClientwill always benilsince the object was just allocated.