Time to time I get error when some configuration is done by admin client and then the configuration isn't set.

It happens only occasionally mostly when keycloak is configured with database.

 
private org.keycloak.admin.client.Keycloak adminClient;

RealmRepresentation testRealmRep = adminClient.realm("testRealm").toRepresentation();
testRealmRep.setRegistrationAllowed(true);
adminClient.realm("testRealm").update(testRealmRep);

and then

adminClient.realm("testRealm").toRepresentation().isRegistrationAllowed() 

returns false and login page doesn't display register link.

failing tests:
org.keycloak.testsuite.account.RegistrationTest;
org.keycloak.testsuite.account.ResetCredentialsTest;

There is link to test result with failed test: https://keycloak-jenkins.rhev-ci-vms.eng.rdu2.redhat.com/view/RH-SSO/job/rh-sso-jpa-matrix/DB=oracle11gR2,jdk=mw_oraclejdk8,label_exp=rhel7/44/testReport/org.keycloak.testsuite.account/RegistrationTest/emptyAttributes/