I have read through multiple questions on the topic of ACL inheritance on Mac OS X, but unfortunately, none seem to be effective in solving this issue in Mojave. They do seem to work on High Sierra, and I have a machine sharing files which is running High Sierra. However, I am now configuring a new Mac Mini Server, which ships with Mojave. A folder created on a share can be deleted from another computer. If I create a folder, then a subfolder inside of that, within a share, then try to delete it from another computer, it throws an error. It says the file cannot be deleted because it is in use. This is even when the computer that created the file is not in the folder in any way (not in terminal, nor in Finder). Only unmounting the share on the computer that created the file seems to allow the file to be deleted. Reapplying ACLs seems to fix the issue, but only until another file is created. Then that new file is not able to be deleted except by the creator, until an unmount has occurred. I have set ACLs recursively using both the group name and the usernames in question. For example:
sudo chmod -R +ai "staff allow list,add_file,search,add_subdirectory,delete_child,readattr,writeattr,readextattr,writeextattr,readsecurity,file_inherit,directory_inherit"
This is after setting up the Shared Folder, and I have also tried setting the POSIX permissions recursively for the group to be able to read, write, and execute. The ACLs look correct when doing an ls -le on the directory.
Again, this seems to work ok in High Sierra. Apple's current server documentation suggesting the creation of a group folder is hilarious, as they have ripped out that functionality. Not available in the Server.app as described. A separate issue is how disrespectful Apple has been in the treatment of its server customers. It's very sad that we can't just pay more to get the functionality we used to get at the price we used to pay.