The Windows Firewall with Advanced Security must block unsolicited inbound connections when connected to a domain.
A firewall provides a line of defense against attack. To be effective, it must be enabled and properly configured. Unsolicited inbound connections may be malicious attempts to gain access to a system. Unsolicited inbound connections, for which there is no rule allowing the connection, will be blocked in the domain.
How this relates to the STIG checklist: STIG vs SCAP benchmark.