It could be because your interface is configured with the Public profile which don’t allow by default to share and use sharing devices/folders on the network
It could be because your Nethserver is not the DHCP/DNS provider and your Windows receive an IP from another DHCP service which don’t have the proper netbios options configured and the DNS don’t contain the information for your Nethserver. But usually if it is your case, you will still be able to reach it will still reachable via the Nethserver IP
It could be because you deactivate a service in your Windows, you have a virus/malware, …
Server side (Nethserver)
It happened to me in the past and mainly it was because nethserver-cups (yum install -y nethserver-cups) wasn’t installed. This package is responsible of Avahi which is a system which facilitates service discovery on a local network.
It could be suricata or threat shield blocking the traffic.
