MongoDB has no primary node after Controller Replacement

Issue

• After replacing a controller MongoDB has no primary node.

[root@controller-3 mongodb]# echo "db.isMaster()" | mongo --host 192.168.24.20:27017
MongoDB shell version: 2.6.11
connecting to: 192.168.24.20:27017/test
{
        "setName" : "tripleo",
        "setVersion" : 2,
        "ismaster" : false,
        "secondary" : true,
        "hosts" : [
                "192.168.24.20:27017",
                "192.168.24.21:27017"
        ],
        "me" : "192.168.24.20:27017",
        "maxBsonObjectSize" : 16777216,
        "maxMessageSizeBytes" : 48000000,
        "maxWriteBatchSize" : 1000,
        "localTime" : ISODate("2019-10-19T13:30:59.253Z"),
        "maxWireVersion" : 2,
        "minWireVersion" : 0,
        "ok" : 1
}
bye