I just deleted 65 pages of notifications going back to 2011. (left most of 2017) Perhaps I ran into some limit after nearly 7 years at 95 pages of notifications and who knows how many actual threads. Hopefully this allows me to get notifications again, as I really miss that feature.
I am still not getting notifications. I've dumped my cashe a few times w/o change. I've tried setting notifications on for entire parts of the forum, but I neither get a notification of new topics in a forum, or any notifications of threads I'm subscribed to, or have posted in. It really diminishes the usefulness of the forum, for me, because I don't see replies to my posts or topics I'm interested in. When I remember to go click the "Show new replies to your posts" I can go check on those threads, but often it's a response to someone else's reply or not anything need to respond to.