remote-class4-get and remote-class4-get-all commands do return valid-lifetime value with mysql db backend

When kea is running db backend in postgresql, and it has no valid-lifetime configured on any level (it uses default value). In the database there is just server tag and class configured.

executed commands, set tag and class:

{'arguments': {'remote': {'type': 'postgresql'},
               'servers': [{'server-tag': 'abc'}]},
 'command': 'remote-server4-set',
 'service': ['dhcp4']}
[
  {
    "arguments": {
      "servers": [
        {
          "description": "",
          "server-tag": "abc"
        }
      ]
    },
    "result": 0,
    "text": "DHCPv4 server successfully set."
  }
]
{'arguments': {'client-classes': [{'name': 'foo', 'test': "member('KNOWN')"}],
               'remote': {'type': 'postgresql'},
               'server-tags': ['abc']},
 'command': 'remote-class4-set',
 'service': ['dhcp4']}
[
  {
    "arguments": {
      "client-classes": [
        {
          "name": "foo"
        }
      ]
    },
    "result": 0,
    "text": "DHCPv4 client class successfully set."
  }
]

get class:

{'arguments': {'client-classes': [{'name': 'foo'}],
               'remote': {'type': 'postgresql'}},
 'command': 'remote-class4-get',
 'service': ['dhcp4']}
[
  {
    "arguments": {
      "client-classes": [
        {
          "boot-file-name": "",
          "metadata": {
            "server-tags": [
              "abc"
            ]
          },
          "name": "foo",
          "next-server": "0.0.0.0",
          "option-data": [],
          "option-def": [],
          "server-hostname": "",
          "test": "member('KNOWN')"
        }
      ],
      "count": 1
    },
    "result": 0,
    "text": "DHCPv4 client class 'foo' found."
  }
]

it's missing valid-lifetime with value 0. OR if that is correct behaviour than the same scenario but using mysql config backend is returning valid-lifetime set to 0 as extra parameter.

In v6 configuration issue is very similar, but instead of returning just valid-lifetime but also preferred-lifetime