Please add the VLAN column to your search officially, I had to do it myself.

proxmox v8.4
in file
/usr/share/pve-manager/js/pvemanagerlib.js
found
replace with
then
systemctl restart pveproxy
or
reboot node
in browser (Ctrl+Shift+N) or Ctrl+F5 page
see:
Datacenter → Search
Node → Search

proxmox v8.4
in file
/usr/share/pve-manager/js/pvemanagerlib.js
found
JavaScript:
columns: rstore.defaultColumns(),
replace with
JavaScript:
columns: (function() {
let cols = rstore.defaultColumns();
cols.push({
header: 'VLAN Tag',
dataIndex: 'vlan',
width: 80,
renderer: function(value, meta, record) {
if (record.data.type === 'qemu' || record.data.type === 'lxc') {
let node = record.data.node;
let vmid = record.data.vmid;
Ext.Ajax.request({
url: `/api2/json/nodes/${node}/${record.data.type}/${vmid}/config`,
success: function(resp) {
try {
let data = Ext.decode(resp.responseText).data;
for (let key in data) {
if (key.match(/^net\d+/) && data[key].match(/tag=\d+/)) {
record.set('vlan', data[key].match(/tag=\d+/)[0].replace('tag=', ''));
break;
}
}
} catch (e) {}
}
});
return record.data.vlan || '';
}
return '';
}
});
return cols;
})(),
systemctl restart pveproxy
or
reboot node
in browser (Ctrl+Shift+N) or Ctrl+F5 page
see:
Datacenter → Search
Node → Search