Good day!
I have an Ubuntu 20.04 server with kea-dhcp 2.4.1 version installed. Everything works fine; the server issues leases. On another ubuntu server, Stork was installed to monitor my kea-dhcp server. Stork shows the server, shows pools, reservations on the server, but does not show dhcp-leases.

kea-dhcp4.conf

{
"Dhcp4": {
    "interfaces-config": {
        "interfaces": ["ens192"]
    },

    "control-socket": {
          "socket-type": "unix",
          "socket-name": "/run/kea/kea4-ctrl-socket"
       },

    "lease-database": {
      "type": "mysql",
      "name": "kea_leasing",
      "user": "myuser",
      "password": "mypass",
      "host": "localhost",
      "port": 3306
    },

    "hosts-database": {
      "type": "mysql",
      "name": "kea_leasing",
      "user": "myuser",
      "password": "mypass",
      "host": "localhost",
      "port": 3306
    },


    "renew-timer": 15840,
    "rebind-timer": 27720,
    "valid-lifetime": 31680,

    "option-data": [
        {
            "name": "domain-name-servers",
            "data": "10.12.15.1, 10.12.15.2"
        },

        {
            "name": "domain-search",
            "data": "mydomain.local"
        }
    ],

    "subnet4": [
        {
            "subnet": "10.100.95.0/24",
            "pools": [ { "pool": "10.100.95.100 - 10.100.95.150" } ],
            "option-data": [
                {
                    "name": "routers",
                    "data": "10.100.95.2"
                }
            ]

            // Add reservations here
        }

        // Add subnets here
    ]
}
}

kea-ctrl-agent.conf

{

// This is a basic configuration for the Kea Control Agent.
// RESTful interface to be available at http://127.0.0.1:8000/
"Control-agent": {
    "http-host": "127.0.0.1",
    // If enabling HA and multi-threading, the 8000 port is used by the HA
    // hook library http listener. When using HA hook library with
    // multi-threading to function, make sure the port used by dedicated
    // listener is different (e.g. 8001) than the one used by CA. Note
    // the commands should still be sent via CA. The dedicated listener
    // is specifically for HA updates only.
    "http-port": 8000,

    // Specify location of the files to which the Control Agent
    // should connect to forward commands to the DHCPv4, DHCPv6
    // and D2 servers via unix domain sockets.
    "control-sockets": {
        "dhcp4": {
            "socket-type": "unix",
            "socket-name": "/run/kea/kea4-ctrl-socket"
        },
        "dhcp6": {
            "socket-type": "unix",
            "socket-name": "/tmp/kea6-ctrl-socket"
        },
        "d2": {
            "socket-type": "unix",
            "socket-name": "/tmp/kea-ddns-ctrl-socket"
        }
    },

    // Specify hooks libraries that are attached to the Control Agent.
    // Such hooks libraries should support 'control_command_receive'
    // hook point. This is currently commented out because it has to
    // point to the existing hooks library. Otherwise the Control
    // Agent will fail to start.
    "hooks-libraries": [
//  {
//      "library": "/usr/lib/x86_64-linux-gnu/kea/hooks/control-agent-commands.so",
//      "parameters": {
//          "param1": "foo"
//      }
//  }
    ],

// Logging configuration starts here. Kea uses different loggers to log various
// activities. For details (e.g. names of loggers), see Chapter 18.
    "loggers": [
    {
        // This specifies the logging for Control Agent daemon.
        "name": "kea-ctrl-agent",
        "output_options": [
            {
                // Specifies the output file. There are several special values
                // supported:
                // - stdout (prints on standard output)
                // - stderr (prints on standard error)
                // - syslog (logs to syslog)
                // - syslog:name (logs to syslog using specified name)
                // Any other value is considered a name of the file
                "output": "stdout",

                // Shorter log pattern suitable for use with systemd,
                // avoids redundant information
                "pattern": "%-5p %mn"

                // This governs whether the log output is flushed to disk after
                // every write.
                // "flush": false,

                // This specifies the maximum size of the file before it is
                // rotated.
                // "maxsize": 1048576,

                // This specifies the maximum number of rotated files to keep.
                // "maxver": 8
            }
        ],
        // This specifies the severity of log messages to keep. Supported values
        // are: FATAL, ERROR, WARN, INFO, DEBUG
        "severity": "INFO",

        // If DEBUG level is specified, this value is used. 0 is least verbose,
        // 99 is most verbose. Be cautious, Kea can generate lots and lots
        // of logs if told to do so.
        "debuglevel": 0
    }
  ]
}
}

agent.env

### the IP or hostname to listen on for incoming Stork server connections
STORK_AGENT_HOST=10.100.95.37

### the TCP port to listen on for incoming Stork server connections
STORK_AGENT_PORT=8080

### listen for commands from the Stork server only, but not for Prometheus requests
#STORK_AGENT_LISTEN_STORK_ONLY=false

### listen for Prometheus requests only, but not for commands from the Stork server
#STORK_AGENT_LISTEN_PROMETHEUS_ONLY=false

### settings for exporting stats to Prometheus
### the IP or hostname on which the agent exports Kea statistics to Prometheus
# STORK_AGENT_PROMETHEUS_KEA_EXPORTER_ADDRESS=
### the port on which the agent exports Kea statistics to Prometheus
# STORK_AGENT_PROMETHEUS_KEA_EXPORTER_PORT=
### how often the agent collects stats from Kea, in seconds
# STORK_AGENT_PROMETHEUS_KEA_EXPORTER_INTERVAL=
## enable or disable collecting per-subnet stats from Kea
# STORK_AGENT_PROMETHEUS_KEA_EXPORTER_PER_SUBNET_STATS=true
### the IP or hostname on which the agent exports BIND 9 statistics to Prometheus
# STORK_AGENT_PROMETHEUS_BIND9_EXPORTER_ADDRESS=
### the port on which the agent exports BIND 9 statistics to Prometheus
# STORK_AGENT_PROMETHEUS_BIND9_EXPORTER_PORT=
### how often the agent collects stats from BIND 9, in seconds
# STORK_AGENT_PROMETHEUS_BIND9_EXPORTER_INTERVAL=

### Stork Server URL used by the agent to send REST commands to the server during agent registration
STORK_AGENT_SERVER_URL=http://10.100.95.38:8080

### skip TLS certificate verification when the Stork Agent connects
### to Kea over TLS and Kea uses self-signed certificates
STORK_AGENT_SKIP_TLS_CERT_VERIFICATION=true


### Logging parameters

### Set logging level. Supported values are: DEBUG, INFO, WARN, ERROR
#STORK_LOG_LEVEL=INFO
### disable output colorization
# CLICOLOR=false

### path to the hook directory
# STORK_AGENT_HOOK_DIRECTORY=```

I set it up according to the official documentation, there are active reservations:

mysql> select * from lease4
-> ;
+———–+—————-+——————————————+—————-+———————+———–+———-+———-+—————————–+——-+————–+——————–+———————-+———+
| address | hwaddr | client_id | valid_lifetime | expire | subnet_id | fqdn_fwd | fqdn_rev | hostname | state | user_context | relay_id | remote_id | pool_id |
+———–+—————-+——————————————+—————-+———————+———–+———-+———-+—————————–+——-+————–+——————–+———————-+———+
| 174350180 | 0x002324D47E78 | 0xFFB6220FEB00020000AB11044C09E0CD6003B3 | 31680 | 2024-05-31 19:26:29 | 1 | 0 | 0 | colibrirud | 0 | NULL | NULL | NULL | 0 |
| 174350181 | 0x0050568440ED | 0x010050568440ED | 31680 | 2024-05-31 22:21:15 | 1 | 0 | 0 | win-sakrvli5241. | 0 | NULL | NULL | NULL | 0 |
| 174350182 | 0xA8A159B70D08 | 0x01A8A159B70D08 | 31680 | 2024-05-31 21:08:45 | 1 | 0 | 0 | mypc.local | 0 | NULL | NULL | NULL | 0 |
| 174350183 | 0x00505684F502 | 0xFF9000A08200020000AB117A9B4BED25A16205 | 31680 | 2024-05-31 21:08:39 | 1 | 0 | 0 | root | 0 | NULL | NULL | NULL | 0 |
+———–+—————-+——————————————+—————-+———————+———–+———-+———-+—————————–+——-+————–+——————–+———————-+———+
4 rows in set (0.00 sec)