[keycloak-user] intermittent 403 while logging in

Hi Team, I am using Keycloak OIDC JBoss EAP 6 adapter and RH-SSO version is 7.2. I updated my app's auth method in web.xml and also added keycloak.json. After creating the client I tried logging in and it worked as expected. However while testing more I saw that sometimes I am getting 403 and the login fails. This is a very random behavior and app works almost 70% of the time. Also I integrated one more app which is using the same Keycloak server as IDP but the app is having a different sub-domain from the first app. Sometimes if I login to one app successfully and then open the other app in the other tab I see this intermittent 403 issue. Its intermittent nature is making it difficult for me to find out the root cause. Any suggestions where to look for such an issue. *ADAPTER LOGS:* 2018-05-14 05:27:15,239 [ajp-/10.7.24.224:8009-15] ERROR [org.keycloak.adapters.OAuthRequestAuthenticator] failed to turn code into token 2018-05-14 05:27:15,239 [ajp-/10.7.24.224:8009-15] ERROR [org.keycloak.adapters.OAuthRequestAuthenticator] status from server: 400 2018-05-14 05:27:15,239 [ajp-/10.7.24.224:8009-15] ERROR [org.keycloak.adapters.OAuthRequestAuthenticator] {"error":"invalid_grant","error_description":"Code not valid"} -- PULKIT GUPTA