This document will address an issue where scanning by OU and excluding machines with FQDN fails to exclude the machine.
You are scanning from a Machine Group setup by OU. You exclude machine(s) by FQDN but they are scanned.
The OU scans the machine using netbios rather than FQDN so excluding machines by FQDN will not work.
Exclude the machines using the netbios name instead of FQDN.