I cannot say why it does not work on your system.
Do you by any chance have apparmor enabled in the default grub cmdline? I recall it was default added at some point.
Or have setup selinux on your system ?
Both can interfere with sharing.
I can replicate a working installation at will and my guides has been created from my notes - they have been tested from scratch using raspberry pi test devices running Manjaro Linux ARM - so I know the basic configuraton works.
I recently banged my head at Samba using a Fedora server - I found that I had to configure selinux to be able access the shares - that made me go back to using Manjaro on my server.
Fedora is the iteration before RedHat Enterprise - so I understand their need to use selinux to harden the services.
I completely fail to don’t understand why you cannot get it work …
If you could provide (it will print the permissions on the content of the folder)
ls -la /Data