Thanks for the hints!

> so...what's your umask?

It's 022.  As far as it's concerned, umask should only be considered when creating a new file, not to affect existing files' modes
(as with the chmod command).  At any rate, the "x" bit in mine is unset, so should not be having the issues what you've seen.

BTW, what's your Samba server's version?  Mine is below:

$ /usr/sbin/smbd -V
Version 4.7.1

Lastly, I mounted the drives via the explorer and they had been marked as "reconnect at login", so they re-mount for me
upon every login and/or after a reboot...  And there have been many of both.

B�KCB��؛[H�\ܝΈ����Y��[����K��؛[\˚[B��TN�����Y��[����K٘\K�B���[Y[�][ێ�����Y��[����K���˚[B�[��X��ܚX�H[��Έ����Y��[����K�[��[��X��ܚX�K\�[\CB�B