Only 1 machine is nothing communicating to server

I have installed agent 2.9 in more than 2000 machines but just one is not working properly.

ERROR:

Starting OCS Inventory Agent on Monday, March 21, 2022 11:03:33.

AGENT => Running OCS Inventory Agent Version 2.9.0.0

AGENT => Using OCS Inventory FrameWork Version 2.9.0.0

AGENT => Loading plug-in(s)

AGENT => Using network connection with Communication Server

AGENT => Using Communication Provider <OCS Inventory cURL Communication Provider> Version <2.9.0.0>

AGENT => Sending Prolog

ERROR *** AGENT => Failed to send Prolog <Server returned nothing (no headers, no data)>

AGENT => Unloading communication provider

AGENT => Unloading plug-in(s)

AGENT => Execution duration: 00:01:28.

service is ok, but it is not showing the machine on the OCS portal.