Cannot update Linux antivirus using /opt/sophos-av/bin/savupdate

Why I cannot update Sophos Antivirus for Linux (v 9.2.3) from corporate server using Primary server http://[server_ip]:8888 and Secondary server http://[server_fqdn]:8888?

I see the following error:

[root@RedHat-Sophos-test ~]# /opt/sophos-av/bin/savupdate 
Downloading http://[server_ip]:8888/CIDs/S000/savlinux/server.inf
Downloading http://[server_ip]:8888/CIDs/S000/savlinux/savlinux/server.inf
Downloading http://[server_ip]:8888/CIDs/S000/savlinux/sdds:SOPHOS/server.inf
Failed to replicate from http://[server_ip]:8888/CIDs/S000/savlinux
Downloading http://[server_fqdn]:8888/CIDs/S000/savlinux/server.inf
Downloading http://[server_fqdn]:8888/CIDs/S000/savlinux/savlinux/server.inf
Downloading http://[server_fqdn]:8888/CIDs/S000/savlinux/sdds:SOPHOS/server.inf
Failed to replicate from http://[server_fqdn]:8888/CIDs/S000/savlinux
Failed to replicate from all update sources

[root@RedHat-Sophos-test ~]#

And no one file with name "server.inf" in BootStrap directory \\SOPHOS\SophosUpdate\CIDs\S000\savlinux

Version of Sophos Enterprise Console  = 5.1.0.1839.