[keycloak-user] Facebook - invalid_grant and "Code not valid"

Hello We are using KC with Facebook. This is working fine when we integrate this into our mobile app. However, on our website (drupal, using https://www.drupal.org/project/openid_connect) we get the following error (in drupal): Could not retrieve tokens. Details: Client error: `POST https://<url-to-keycloak>/auth/realms/myrealm/protocol/openid-connect/token` resulted in a `400 Bad Request` response: {"error":"invalid_grant","error_description":"Code not valid"} Does anyone know what might be causing this? Thanks