Hi Thierry,
Thank you for posting, I am here to help you. A custom icon from a UNC path may not be loading in Windows 11 25H2 due to security hardening that restricts the use of remote paths for file shortcut icons
To fix this follow this steps:
Open Group Policy Editor then navigate to, Computer Configuration and click Administrative Templates. Click Windows Components then File Explorer
Click Enable Allow the use of remote paths in file shortcut icons. On top of the above steps, you may also need to create a registry key:
Open Registry Editor
click Start button and search regedit then navigate
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Explorer
Inside Explorer folder create a new DWORD key Value Name EnableShellShortcutIconRemotePath Value Type REG_DWORD Enabled Value 1 Disabled Value 0
Let me know how this goes. Looking forward to helping you out. If you need more help please feel free to let me know. If the answer is helpful, please click "Accept Answer".
Best regards,
Jansher