This may be due to the following reasons
Proxy/Firewall in the machines may block the communication to Freshservice.
If the asset limit is reached, new assets would reach to Trash folder within Inventory
If the asset was already scanned and identified in a different name with a different serial number then the updates would be reflected over the existing asset.
Reach out to our support team at firstname.lastname@example.org for any assistance on the same.