NARG alarms coming as root cause.

HI All

I have a issue where Port down is causing  the  associated NARG to go down and the NARG down alarm is coming as IsRoot Yes  I would expect NARG down to come as the impact of Port down.

The port down alarm is derived from the model file using below.

interface BT_Port: NetworkAdapter
"Generic Port object, which will be used in the devices which are not allowed to discover."
{
        propagate attribute boolean or BT_System_Status = BT_Switch,PartOf,IsUnresponsive;
        propagate attribute boolean BT_Card_Status = BT_Card,RealizedBy,IsCardNotOperating;
        propagate attribute boolean BT_Parent_Card_Status = BT_Card,RealizedBy,BT_Parent_Card_Status;
        computed attribute boolean BT_Port_Status = !BT_System_Status && !BT_Card_Status && IsNetworkAdapterNotOperating && !BT_Parent_Card_Status;
        event BT_PortMightBeDown "Based on system, card and port status" = BT_Port_Status;
        refine problem Down "Port is Down" => BT_PortMightBeDown, BT_PortMightBeDown explains;
        export Down;
        void insertPortValues(in string mtosi, in string btvendor, in string btmodel, in string location, in string resState, in string desc, in string displayname, in string deviceid)
                definition:
                BT_MTOSI = ((mtosi == "") ? BT_MTOSI : mtosi) , BT_Vendor = ((btvendor == "") ? BT_Vendor : btvendor) , BT_Model = ((btmodel == "") ? BT_Model : btmodel) , BT_Location = ((location == "") ? BT_Location : location),DisplayName = ((displayname == "") ? DisplayName : displayname),Description = ((desc == "") ? Description : desc),DeviceID = ((deviceid == "") ? DeviceID : deviceid),BT_Resource_Status = ((resState == "") ? BT_Resource_Status : resState);

}

Also below is the output of script

START {

} do {

   print("The problem ".class."::".instance."::".event);

   print("explainedBy    ".getExplainedBy(class,instance,event))?LOG,IGNORE;

   print("explains       ".getExplains(class,instance,event))?LOG,IGNORE;

   print("causes         ".getCauses(class,instance,event))?LOG,IGNORE;

   print("causedBy       ".getClosure(class,instance,event))?LOG,IGNORE;

   stop();

}

./bin/sm_adapter --server=N-ND-APM --broker=<> -Dclass=BT_Port -Dinstance=PORT-3035/pdh1/6 -Devent=Down getExplains.asl | tee The problem BT_Port::PORT-3035/pdh1/6::Down

explainedBy    {  }

explains       { BT_Port::PORT-3035/pdh1/6::BT_PortMightBeDown }

causes         {  }

causedBy       { BT_Port::PORT-3035/pdh1/6::BT_PortMightBeDown }

[root@linbgl150 smarts]#

Can someone here please tell me what is mssing in the model file as NARG corelation ha stopped post this change.

Thanks in advance.