Changing an ACL should generate a FILE_NOTIFY_CHANGE_SECURITY notification. Looks like the code to trigger this was never added to smbd.
Oh good catch. Should be only one place that needs changing, set_sd() inside source3/smbd/nttrans.c.
(In reply to Jeremy Allison from comment #1) Yup. Plus some basic smoke tests.
This bug was referenced in samba master: 29e51f3ed935d0475b1715f82560ee356ab5e401 2be7c0c2f927042843fb8a2ea0b9c67d1f969d00
Created attachment 18770 [details] Patch from master for v4-23-test
Created attachment 18771 [details] Patch from master for v4-22-test