Reply notices not showing up

(Feel free to delete, guess it isn't on my end after all!) 

.

This should start in bug report but I'm not confident this isn't 
an issue on my end. Recently I have stopped receiving notices 
about replies to threads and have to check them manually.
I have my settings to automatically as is: "Instant pm notif".
I even manually use that option each time I post a thread, even
though a few months ago that was already being done for me 
automatically. I'm not sure what else there is I need to do, so I
would love suggestions.