diff --git a/app/services/cwmp/main_state_machine.ts b/app/services/cwmp/main_state_machine.ts
index 4bd732f..747005b 100644
--- a/app/services/cwmp/main_state_machine.ts
+++ b/app/services/cwmp/main_state_machine.ts
@@ -54,6 +54,15 @@ class IdleState extends DeviceState {
       return { nextState: new CriticalReadsState(), response: '' }
     }
 
+    // If device is already classified (GPN supported + has parameters), skip GPN test
+    if (device.gpnStatus === 'supported' && device.getParameters().length > 0) {
+      logger.info(
+        { gpnStatus: device.gpnStatus, paramCount: device.getParameters().length, deviceId: device.identifier },
+        '[IdleState] Device already classified — skipping GPN test'
+      )
+      return { nextState: new CriticalReadsState(), response: '' }
+    }
+
     logger.info(
       { gpnStatus: device.gpnStatus, circuitBreaker: device.gpnCircuitBreaker, deviceId: device.identifier },
       '[IdleState] GPN allowed — proceeding to discovery'
@@ -239,7 +248,9 @@ class CriticalReadsState extends DeviceState {
       }
     }
 
-    if (context.device.gpnStatus !== 'supported') {
+    // Only reclassify via catalog if GPN is not supported AND device hasn't been classified yet
+    // (i.e., no parameters exist — all are still stored as properties)
+    if (context.device.gpnStatus !== 'supported' && context.device.getParameters().length === 0) {
       reclassifyDeviceFromCatalog(context.device)
     }