thank you for your article, but i have a problem when i run the code to SignInWithWebUI it shows nothing on the screen and show this in debug console: D/AWSMobileClient( 8356): onSuccess: HostedUI signed-in D/AWSMobileClient( 8356): _federatedSignIn: Putting provider and token in store 2 D/AWSMobileClient( 8356): Inspecting user state details 2 D/AWSMobileClient( 8356): hasFederatedToken: false provider: cognito-idp.us-east-1.amazonaws.com/us-east-1_iRPlAFvH1 D/AWSMobileClient( 8356): onResult: Federation from the Hosted UI succeeded W/le.amplify_tes( 8356): Long monitor contention with owner Thread-12 (8497) at void com.amazonaws.mobile.client.AWSMobileClient.federateWithCognitoIdentity(java.lang.String, java.lang.String)(AWSMobileClient.java:1943) waiters=0 in void com.amazonaws.mobile.client.AWSMobileClient.federateWithCognitoIdentity(java.lang.String, java.lang.String) for 1.633s D/AWSMobileClient( 8356): hasFederatedToken: true provider: cognito-idp.us-east-1.amazonaws.com/us-east-1_iRPlAFvH1