Notifications delete themselves the moment you try to activate them, and then forward you onto the relevant page. That creates problems when it fails to forward you on.
It's relatively often I'll double-click or double-tap a notification, or get an internet hiccup on the notification page so that I don't get forwarded and have to refresh. Both of these things mean I see a ":( That notification doesn't exist!" error. This used to catch me out sometimes and I'd get notification about some comment in feedback, then I'd see this error and have no idea what happened where.
Could notification pages be available a bit longer?
Alternately, maybe notification pages shouldn't be a thing! Instead, just link me straight to that page, and when I land on that page, it clears any notifications it might have for me. That would also resolve a related issue I've brought up.