Your event log contains errors with Event ID 34054 for Central Quarantine Server (CQS). In the Quarantine Console, in Symantec Central Quarantine Properties, on the General Errors tab, the message "Attention: download: Qserver cannot connect to the gateway to download definitions" appears.
Central Quarantine is working as designed. If the Digital Immune System (DIS) servers are busy when Central Quarantine tries to contact them, they request that Central Quarantine try to contact it again later. When that happens, Central Quarantine logs this message and then tries again at a later time.