I just missed mention because the notification never popped up.
I've also noticed that when I get the drag down hover menu for the notifications won't stay open unless you keep the courser in just the right spot.
Anyway, when I went to the thread that the lacking notification mention was in all the previous posts on the page disappeared until I refreshed the page.
The same thing happened on the mobile app in the same thread and in the PYP thread.
I'm wondering if it doesn't have something to do with all the spoilers?