sorry, my message came from this reasons:
1. I'm new into devel list and development under Fedora.
2. is a common issue under Fedora update by real developers how works with dnf.
3. I find something into google search about hidden groups but I'm not sure that is true into this bug.
into last few years Fedora come with many users accounts so
I'm wary at first indications of the reasons above.