yesss that happened to me on the evening of the first day after this update from hell was implemented. Thankfully I, in a panic, stumbled upon the 'mark all as read' button to get rid of it before I had a chance to write a question about it. I feel your pain though... surprising how much more irritating a notification gets when you know what's behind it but it just won't go away.
ngl, I was super close to just unfollowing the person then letting them know what had happened so that they didn't assume I was super passive-agressive or something. :P