We tested both 3.5.16 and 3.6.8, the same issue exists in both versions.

Test steps:
1. create a DFS share, say share1, which points to an internal hidden share _share1$
2. create a new folder "xptest", clean up all default ACLs and add two users with full access control
3. create a subfolder "xptest\testdir", and a file "xptest\testfile" inside this xptest folder
4. add a new user with full access to the folder "xptest", and let it apply to itself, and subfolders
5. the file "testfile" now has 3 ACE entries, which is correct, as it inherited the new ACL change from parent
6. the directory "testdir" still has 2 ACE entries, the newly added ACL entry did not propagate to this folder.

Same test on internal share does not have this problem.