It’s actually rockstor’s ‘default’ smb.conf file that is broken, the default in Leap15.1 (our main focus) and presumably Tumbleweed already has this line in place. We are planning to do things differently here than we have done to date and have already implemented our newer system to get docker working in the two openSUSE targets. If you take a look at @Flox recently opened issue you will see what is planned. This looks very much like it will sort the problem you encountered.
Well done on finding the fix but the fault is all ours as we overwrite the smb.conf with a now old, and fine for CentOS template. We are moving to sourcing the package default found and edit it to create our initial template, such as we now do for docker (in our openSUSE variants only).
Thanks for sharing your work around, and until we get this recent issue’s pull request prepared and merged your advise is relevant. Do take a look at the issue though as @Flox indicates the where and what of the upstream distro’s default samba which for those having difficulties is an important reference untill we get out ‘old ways’ template system updated. @def_monk and @Flox have just been battling with samba so more input on this is very timely. Thanks again.
Do also take a look at the btrfs backport comparisons between Leap15.1 and Tumbleweed in the following post as Leap 15.1 is kept surprisingly up to date on these:
Thanks again for sharing your findings and do keep the reports coming. Much appreciated.