So I have (or should say HAD) set my Email Preferences to “Unsubscribe from ALL”.
Today I checked again as I’m getting into the habit of periodically checking all my settings in plex and “Email me when someone reports an issue with my library or replies to an existing issue” has been added and its auto enabled ON
That’s the issue, it appears it doesn’t. I had this set to Unsubscribe from ALL and as you can see from the screenshot below, it has the confirmation check. However, plex have changed this setting which I set, disabling it and in addition also added a new preference and auto enabled it.