I struggled with the weirdest permission issues when I created files on Samba shares from MacOS. I have entered this option in the SMB/CIFS config options and this seems to have fixed my problem:
fruit:nfs_aces = no
You can find more information at the very bottom of the following page: https://wiki.samba.org/index.p…Work_Better_with_Mac_OS_X.
Just try and see if this helps. You probably have to do a reset share folder permission first.