A bug that's been around for far too long, so I went looking for the forums. It's moved. I set up a new account. Logged in. I did a search, and yeah my patience ran out. So here goes, before my "human" validation runs out again.
I'm on a pretty much latest update of android. For a long time, I've been missing out on notifications. Missing notifications include (but I have no idea of a full list) troops ready, statues finished, buildings done, notifications from the game about hammerman etc, boosts running out. Notifications I still get include pinned messages in chat (thank god) and 2 hours before end of ops (phew!). I assume that there's a pattern there.
It's a quality of game play thing: most of the game is spent waiting for something to happen, it'd be lovely to have the option of knowing again. So that's my report, and hopefully some day in the next few years these will come back.