This is sounding like a case of users will be users.
As you suggested, I think my moderator is dealing with a user that can't find their confirmation (or understand they need to reply to it). So the moderator tried to override things by trying to add them in by using the "mass subscribe" operation.
It sounded on Github that some opinion was that it wasn't necessary to see these pending requests, but as "users will be users" I think would be useful to see what is in queue for subscription requests, it would be better yet to be able to either clear them out or accept them there. But at very least seeing them there would go a long way helping out my moderators troubleshoot.
On another request, user found the confirmation email, replied, and was accepted. However that email was several weeks old. So I'm guessing our default for expiration of requests is not the default of 3 days. But I haven't been able to find that setting. Is that in Postorius somewhere or will I need to change with the shell?
I wonder if temporarily changing the Subscription Policy to "open" would allow those in pending to be accepted and clear that queue out?
Thanks again for the input, much appreciated!
CoastAlaska, Juneau, Alaska