since you’re using a command endpoint for the agent hosts, their host object and corresponding apply rules for services should be put into the
master zone. You’re mentioning a
hosts.conf file, please move this into
/etc/icinga2/zones.d/master and validate the configuration again - then it will generate service objects visible via
icinga2 object list --type Service as well.
You can verify the loaded and included configuration files with enabling the more verbose log level on config validation like this:
icinga2 daemon -C -x notice
Grep for the specific file name in there to see whether it is loaded.
PS: Don’t use
conf.d in distributed setups, this is discouraged and as such, disabled with the setup wizards by default.