Apparently there is a new kinja bug that dismisses comments after someone posts them. A few comments from my last post have disappeared, and some of them didn’t even show up in my notifications at all. I also noticed some of my responses to comments immediately disappearing after I post them. On top of that, I can’t even edit my comments anymore!
If you notice your comments disappearing, the person may not be dismissing them, it may just be a bug.