Reply for both above:
I connect to a remote share using the fstab with a mount statement from 16.04. The Mint is merely a VM host for this application.
As far as what may have been updated . . . literally everything. I wasn't paying too much attention to when this happened. But here's how I discovered it.
I have a script that runs via cron each night. It creates a backup of my production directories/files to a compressed tar and stores the resulting file on the remote share. That seems to work just fine. But because space is always limited the creation is followed by bash code that deletes all the archives beyond the most recent 7. This is not happening now and if I try it manually (via the CLI) it reports that the file(s) are not found. Here are some examples:
This is a partial list of archive files created by the tar. I displayed these with the command "ls -1 BKUP* "
BKUP_2018-05-21_02:00:01.gz
BKUP_2018-05-22_02:00:01.gz
BKUP_2018-05-23_02:00:01.gz
BKUP_2018-05-24_02:00:01.gz
BKUP_2018-05-25_02:00:01.gz
BKUP_2018-05-26_02:00:01.gz
However, when I try to delete one/many/all of them with:
$rm BKUP_* is get the following response:
BKUP_2018-05-22_02:00:01.gz
BKUP_2018-05-23_02:00:01.gz
BKUP_2018-05-24_02:00:01.gz
BKUP_2018-05-25_02:00:01.gz
BKUP_2018-05-26_02:00:01.gz
$ rm BKUP_2018-05-26_02:00:01.gz
rm: cannot remove 'BKUP_2018-05-26_02:00:01.gz': No such file or directory
Now, if I look at that directory using the Mint filemanager I see the following:
With Samba (SMB) this translation is called "file name mangling". The original reason was that old DOS and early Windows systems could only work with the 8.3 file name scheme so the actual name would be translated to something else to substitute. Again, I have ALL of these options turned off in all the smb.conf files I could find.
And I'm starting with the assumption that the mangling is happening on the smb side in the ASUS firmware. But this is just an assumption (one has to start somewhere).
So before I dig deeping into the 16.04 samba config I am posting here with the hope that someone is familiar enough to isolate where the cause might be.
Thanks for reading. Hope this clears up what is happening.