OSX 10.14 Mojave SMB locking files and not releasing them
I have this same issue. It seems to only be with Microsoft Office files. PDFs don't seem to have "permanent lock" issue. I don't know if it's a problem with the MacOS "dual fork" file structure fighting with the Microsoft temporary lock file.

I've re-pushed NTFS permissions down from the parent folder to see if that would resolve the creation/destruction of the temporary files. It works for a bit then the problem comes right back.

We have even had one file where all permissions were removed and even the SYSTEM user was unable to recover the permissions. I couldn't seize ownership with the GUI or any cmd commands. I had to restore the file from a backup.

Have you had any luck with this issue?

I've tested the glitch with a laptop that is running the same versions of MacOS and Office but have been unable to trigger the lock file issue.