Is that asset still in AD, @Chiaravalli ?
Personally, I've moved disabled devices in AD to a "disabled OU" so I could track them for future. If your scanner is scanning a "disabled" OU where you may have moved that asset, it could continue to populate.
Or, are you scanning Azure Intune where that asset may still be present?
Another far fetched idea is DNS issues. Is that device removed from DNS?
Keep us posted how it goes.
Tim N.
Lansweeper Employee