iA have pushed a fix for the WordPress authorisation issue so, if you're reading this it's worked 👍
There's a bug somewhere when someone unsubscribes from the daily emails or muse-letter, it's this glitch which removes the commas from the list of email addresses.
I received an unsub mail with no details so suspected something was wrong, sure enough when I looked in the database the same thing had happened. Looks like I'll need to dig in to find out what's happening.
Hopefully, the bug has been fixed. I've done some tests and everything looks okay.