In our system, non-staff users have an empty /tags page, and they also see no tags in the edit tags navigation pop-up. Users can use tags to tag posts, see the tags in tagged post, click on the tags etc. etc.
We don’t use tag groups, there are no default navigation tags. We may have played around with those settings in the past, so I suspect it is some setting I don’t find, or an artifact/bug from past experimentation. Any hints where to look?
Just a small update on this - I believe this behaviour has actually been changed in this new commit:
If you update your site, users should now be able to have tags they have group-permission to see show up in their sidebar selector without needing to set include secure categories in tag counts.