In the JSON generated by vmware.vm.discovery all discovered VMs have an empty "tags" element, even if vmware tags are actually defined in vSphere. It seems taht restarting zabbix_proxy, in most cases, makes appear tags again in the JSON. 

Since we use vmware tags to filter VMs that need to be discovered and monitored, this issue makes hosts to be randomly created and deleted from zabbix.

Steps to reproduce:

1. Create an host and apply VMware FQDN template

2. In the vmware.vm.discovery[] discovery rule: add a Javascript preprocessing step in order to write lld output to the logs

var obj = JSON.parse(value);
Zabbix.log(3, "VMdiscovery: "+JSON.stringify(obj));
return JSON.stringify(obj);

3. Observe JSON output in zabbix_proxy.log: "tags" element is empty.

843683:20230418:100956.685 VMdiscovery: 
      {
    "{#VM.UUID}": "503a502b-4ed7-b865-9999-8d0e514e34b6",
    "{#VM.ID}": "vm-28941",
    "{#VM.NAME}": "adfs01",
    "{#HV.NAME}": "xxxxxxxmgt03",
    "{#HV.UUID}": "4c4c4544-005a-3410-9999-b6c04f314c32",
    "{#HV.ID}": "host-21",
    "{#DATACENTER.NAME}": "xxxxxxxmgm01",
    "{#CLUSTER.NAME}": "xxxxxxxmgm01",
    "{#VM.IP}": "192.168.2.10",
    "{#VM.DNS}": "adfs01.xxxxxx",
    "{#VM.GUESTFAMILY}": "windowsGuest",
    "{#VM.GUESTFULLNAME}": "Microsoft Windows Server 2016 or later (64-bit)",
    "{#VM.FOLDER}": "xxxxxx-infrastructure",
    "{#VM.SNAPSHOT.COUNT}": 0,
    "{#VM.TOOLS.STATUS}": "guestToolsRunning",
    "{#VM.POWERSTATE}": "poweredOn",
    "{#DATASTORE.NAME}": "xxxxxx-02-ntx-mgm",
    "{#DATASTORE.UUID}": "399972f4-f7529f1a",
    "{#VM.RPOOL.ID}": "resgroup-28833",
    "{#VM.RPOOL.PATH}": "xxxxxx-infrastructure",
    "vm.customattribute": [
      {
        "name": "LastBackupStatus",
        "value": "Successful: 2023-04-18 03:06:00 UTC"
      },
    ],
    "tags": []
    },

....

    ]

4. Restart zabbix and look again at zabbix-proxy.log: "tags" element is now properly collected.

# systemctl restart zabbix-proxy
# systemctl status zabbix-proxy

zabbix-proxy.service - Zabbix Proxy
   Active: active (running) since Tue 2023-04-18 11:01:53 CEST; 

3819356:20230418:110956.470 VMdiscovery: 
    [
    {
      "{#VM.UUID}": "503a502b-4ed7-b865-9999-8d0e514e34b6",
      "{#VM.ID}": "vm-28941",
      "{#VM.NAME}": "adfs01",
      "{#HV.NAME}": "xxxxxxxmgt03",
      "{#HV.UUID}": "4c4c4544-005a-3410-9999-b6c04f314c32",
      "{#HV.ID}": "host-21",
      "{#DATACENTER.NAME}": "xxxxxxxmgm01",
      "{#CLUSTER.NAME}": "xxxxxxxmgm01",
      "{#VM.IP}": "192.168.2.10",
      "{#VM.DNS}": "adfs01.xxxxxx",
      "{#VM.GUESTFAMILY}": "windowsGuest",
      "{#VM.GUESTFULLNAME}": "Microsoft Windows Server 2016 or later (64-bit)",
      "{#VM.FOLDER}": "xxxxxx-infrastructure",
      "{#VM.SNAPSHOT.COUNT}": 0,
      "{#VM.TOOLS.STATUS}": "guestToolsRunning",
      "{#VM.POWERSTATE}": "poweredOn",
      "{#DATASTORE.NAME}": "xxxxxx-02-ntx-mgm",
      "{#DATASTORE.UUID}": "399972f4-f7529f1a",
      "{#VM.RPOOL.ID}": "resgroup-28833",
      "{#VM.RPOOL.PATH}": "xxxxxx-infrastructure",
      "vm_customattribute": [
        {
          "name": "LastBackupStatus",
          "value": "Successful: 2023-04-18 03:06:00 UTC"
{{        }}}
      ],
      "tags": [
        {
          "name": "IT-OPERATION",
          "description": "",
          "category": "Monitoring-Department"
        },
        {
          "name": "YES",
          "description": "",
          "category": "Monitoring-Agent"
{{        }}}
      ]
    },
    
    ....
    
    ]