Mongodb findOneAndUpdate function is inserting new document

I just need to update serviceActiveFlag status whenever i make an update api call.After an update api call,i can see a new document with empty vehicle array is created as shown below.

_id:59c76073c11d3929148f500f
vehicle:Array
_v:0

id field will override upon every put api call.

Can some one help me to resolve this issue?

schema

var localTransportSchema = new Schema({

        name: { type: String, required: false, trim: true },
        contact: {
            addressLine1: { type: String, required: false },        
            serviceActiveFlag: { type: String, required: false, enum: ['Y', 'N'] },
    }, 
    vehicle: [{
        vehicleType:{ type: String, required: false, enum: ['sedan', 'hatchback', 'suv', 'mpv', 'luxury'] },        
    }]
});
module.exports.accomodationModel = mongoose.model(collection, localTransportSchema);

controller

var updates = {
            $set: {
                "contact.addressLine1": req.body['addressLine1'],                
                "contact.serviceActiveFlag": req.body['serviceActiveFlag']
            }
    };

    transportModel.findOneAndUpdate({ "name": req.body['providerName']},
        updates, { returnOriginal: false, upsert: false }, function (err, doc) {
            if (err) {
                logger.error("Error while updating record : - " + err.message);
                return res.status(409).json({
                    "Message": "Error while updating transport details for provider " + req.body['providerName'] + " in transport details table"
                });
            } else if (doc === null) {
                logger.error("Error while updating record in transport details : - unable to update database");
                return res.status(409).json({
                    "Message": "Error while updating transport details for provider " + req.body['providerName'] + " due to " + err.message
                });
            }
        });