[2.3] Cannot download multiple test results with API/CLI client

I have run "fio" test with MAAS:
$ maas admin machine test cbk88g testing_scripts=fio

And the results are recorded as "id=108" with 1 NVMe and 5 HDDs. However, when downloading the result of "id=108", it only outputs the result of one NVMe drive. 5 remaining HDDs' results are not exposed with API/CLI client.

$ maas admin node-script-result read cbk88g 108
{
    "last_ping": "Sun, 11 Mar 2018 08:27:35 -0000",
    "ended": "Sun, 11 Mar 2018 08:27:35 -0000",
    "status": 2,
    "type": 2,
    "started": "Sun, 11 Mar 2018 07:26:39 -0000",
    "id": 108,
    "resource_uri": "/MAAS/api/2.0/nodes/cbk88g/results/108/",
    "runtime": "1:00:56",
    "type_name": "Testing",
    "status_name": "Passed",
    "results": [
        {
            "starttime": 1520753199.904428,
            "created": "Sun, 11 Mar 2018 07:22:13 -0000",
            "exit_status": 0,
            "status": 2,
            "started": "Sun, 11 Mar 2018 07:26:39 -0000",
            "id": 750,
...
            "parameters": {
                "storage": {
                    "value": {
                        "name": "sdd",
                        "model": "HGST HUS726040AL",
                        "id_path": "/dev/disk/by-id/wwn-0x5000cca25dee3c1f",
                        "physical_blockdevice_id": 31
                    },
                    "type": "storage"
                }
            },
            "estimated_runtime": "1:00:55",
            "updated": "Sun, 11 Mar 2018 08:27:35 -0000",
            "script_id": 15,
            "name": "fio",
            "script_revision_id": 15
        },
        {
...
            "parameters": {
                "storage": {
                    "value": {
                        "name": "sdb",
                        "model": "HGST HUS726040AL",
                        "id_path": "/dev/disk/by-id/wwn-0x5000cca25dee6c79",
                        "physical_blockdevice_id": 29
                    },
                    "type": "storage"
                }
            },
...

^^^ Multiple HDDs are there.

$ maas admin node-script-result download cbk88g 108 output=all | grep command:
Running command: sudo -n fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1 --name=fio_test --bs=4k --iodepth=64 --size=4G --filename=/dev/nvme0n1 --readwrite=randread
Running command: sudo -n fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1 --name=fio_test --bs=4k --iodepth=64 --size=4G --filename=/dev/nvme0n1 --readwrite=read
Running command: sudo -n fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1 --name=fio_test --bs=4k --iodepth=64 --size=4G --filename=/dev/nvme0n1 --readwrite=randwrite
Running command: sudo -n fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1 --name=fio_test --bs=4k --iodepth=64 --size=4G --filename=/dev/nvme0n1 --readwrite=write
Running command: sudo -n fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1 --name=fio_test --bs=4k --iodepth=64 --size=4G --filename=/dev/nvme0n1 --readwrite=randread
Running command: sudo -n fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1 --name=fio_test --bs=4k --iodepth=64 --size=4G --filename=/dev/nvme0n1 --readwrite=read
Running command: sudo -n fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1 --name=fio_test --bs=4k --iodepth=64 --size=4G --filename=/dev/nvme0n1 --readwrite=randwrite
Running command: sudo -n fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1 --name=fio_test --bs=4k --iodepth=64 --size=4G --filename=/dev/nvme0n1 --readwrite=write

^^^ Only NVMe.