Not sure if this is the correct place to report the issue on https://wiki.omv-extras.org/doku.php?id=omv7:omv7_plugins:docker_compose#if_we_need_communication_between_the_containers_and_the_host
The "192.168.1.224/28" should match to the ip range example mentioned early in this wiki as 192.168.1.240/29 when creating the macvlan.