Problem with volume import and setting share permissions.

I previously did some experimants with volume export and import and found it worked quite well.  One thing that happens is that all sharing permissionas are wiped, the shares show up as "not shared".  I can understand why that would need to be, since the user list from the old and new may not match.  But all I had to do the last time was go in and set them up.  That previous testing was some time ago, under OS6.9.x or maybe even 6.8.x.

I was running another specific experiment recently and found that it's now broken.  Trying to set SMB permissions for a share on an imported volume results in this:

If you "Ignore", the GUI makes it look like it worked anyway, but the share is not actually made available and rebooting makes the GUI again show the share as not shared.

So I thought maybe I'd disable and re-enable SMB at system level.  Trying to disable SMB results in this:

Interestingly, if I restore a configuration from the old NAS from which the volume was exported (and where it was the only volume), all is fixed.

And before anyone asks, the volume names are different and there are no duplicate share names except in home folders (where it cannot be avoided).