Bootstrap script should be only returned when boostrap parameter is present regardless if host is found or not, because it can be actually found by a HTTP proxy REMOTE_IP fallback mechanism and bootstrap would be never returned.

Second problem is in global template handling, it should be only returned when host was not found but there wasn't mac argument provided.

More info at: https://community.theforeman.org/t/foreman-2-4-katello-4-ipxe-not-working/23398