[keycloak-user] Offline_access token expires or goes stale in random manner

Hello, I had set offline access token for a lot of users at the same time. Their Offline Session Idle timeout has been set to a very high number so that it expires rarely. But I have noticed lately that some of the tokens are expiring in random manner. No clue what's the problem and how can I debug. Can you throw some light on what the problems might be? I have a setup of 3 node keycloak instance talking to each other via muticast protocol. Regards, Soumya