I'm not seeing an alert on every page I'm watching. I'll see some alerts, but when I look through the forum I see people have posted on threads I watch with no alert ever being sent.
I think if you haven't looked at a page after a certain period of time it won't alert you anymore until you look at it again.
I've noticed the same in the last few days. I only follow a handful of threads, nearly all of them in the Mod-Zone and yesterday a whole page's worth of posted conversation betwixt my fellow mods went un-alerted to me. I felt sad and alone like I had cooties or something.
Seriously, folks, you need to pay attention because assuming you even know who Charo is (I do) you are not likely to see another segue for a Charo ref taken advantage of in your natural lifetime. This is like seeing Haley's Comet.
This is most likely what was happening. Alerts disappeared after four days, even if you don't view the forum, I believe. I just changed it to seven days; let me know if that seems like too long and they pile up.