I get notifications, about once per week, for threads I've long unsubscribed from.

Each of these 10 to 20 notifications, once a week, includes notifications for multiple "new" comments, all of which are not new, and usually are about a week or two old, and I've already read these comments. Sometimes they're for threads I'm still subscribed to, most times it's for threads I am no longer subscribed to.

This has been an issue for a couple of years now, and I would love to see it fixed.