I refreshed my home page and got seven new notifications (red bubble with the number 7 and the observations at the top of my dashboard). I figured I was being tagged recently, but the dates are all from two or three years ago, but they just showed up now?
I don’t know that this is necessarily what happened, but if they edit the comment to tag you, I believe you will get a notification but the date of the comment will still be listed as the date when it was originally created. (It seems people do this sometimes, though I don’t understand the logic of why they prefer this to adding a new comment.)