I don't know if this is a sign of a problem. All my instincts tell me it is user-error, but just in case it isn't, I'm reporting it here.
I have a group member with two apparent but related problems:
(1) He keeps finding his subscription changed to one of the Daily Digest or Summary settings. He wants individual messages only.
(2) He keeps finding himself unsubscribed from the group. This happened several times today alone, but before too.
He says he doesn't do these things. But there is line after line of "(name) <address> left via web" followed by "(name) <address> resumed membership via web".
Every time he re-subscribes, his account is mysteriously set to one of the Digest or Summary settings even though it had previously been set to Individual Messages. It seems to be random which one it goes to. That new setting apparently happens AUTOMATICALLY when he re-joins, because there is nothing in the activity log showing a change TO those Digest/Summary settings. (Well, there were a couple, but those were earlier.) Then we change him back to Individual Messages. And a few minutes later he has "left via web" again. And then re-joins a minute later. And we have to change him back to Individual Messages again. And around we go.
I don't know what he is doing (if anything) that triggers leaving via web. He claims he didn't do that.
Obviously, he is fed up with Groups.io.
He changed himself back to Individual Messages yesterday, then today received an email message saying that he had been unsubscribed and he can re-subscribe within 7 days. Could there be something stuck in a cache, somewhere?? He uses Edge, IE, and Chrome. Do any of these have problems with the Groups.io web interface?
All changes were "via the web"; so nobody sent email messages to unsubscribe him.
Someone else could know his password and has been doing this, so we told him to change his Groups.io password.
There is one other oddity. He says his email gateway (where he works?) bounces the first message from every new address, which they do to cut down on spam. He has a record of bounced messages from "firstname.lastname@example.org", "email@example.com", etc. which their server bounced because every one came from a previously unknown sender. Yet, his Groups.io account shows no record of any bounces, and there is nothing in the Activity log about bounces from his address. Ever.
Any clue what's going on? Like I say, it sounds to me like he clicks the wrong buttons, but why does it keep happening without him knowing it?
Arrgh, he just got unsubscribed again! This time when he re-subscribed, it came back with "Special Notices Only".