Missing Item prototypes on clone or import/export when linked to another template

Steps to reproduce:

1. Create a first template named "Test root"
2. Create a discovery rule named "DCV - VFS", (Type:Zabbix Agent (active), key:vfs.fs.discovery)
3. Create a item prototype in this discovery rule (Type:Zabbix Agent (active),vfs.fs.size[ {#FSNAME},pfree])
   # Create a second template named "Test linked"
   # Link "Test root" on "Test linked"
   # Always in "Test linked" configuration template, go to discovery rule , open "DCV - VFS" and add item prototype (Type:Zabbix Agent (active),wmi.get["root\CIMV2","SELECT PercentIdleTime FROM Win32_PerfFormattedData_PerfDisk_LogicalDisk WHERE Name LIKE '%{#FSNAME}

   %'"])

4. Go to Configuration > Template, search "Test linked" and try to Full Clone, named "Clone of Test linked"
5. Open "Clone of Test linked", go to Discovery rules. The full clone have not clonned all item prototype.
6. Export "Test linked"
7. Delete "Test linked"
8. Import "Test linked"
9. Open "Test linked", go to Discovery rules. The export/import have not fully receated Template.

Result:
In video in attachment, the second Item prototype "VFS - Volume "

" : Active time in %" is not cloned or exported.
Expected:
Full Clone or Import/Export functions recreate all items, including linked prototype items.

This issue occure on Zabbix 5.4 production and 6.0.4 test lab.