My notifications have been 4 to 10 hours late since yesterday.
Edit: some of my notifications, that is. Others appear within 30 minutes.
Being Android user I'm rather used to notifications in general happening hours later than they should, or just not happening at all, so I wouldn't even notice something like this, but I've been getting some 503 errors this morning so it's all likely just related to ernest working on things: https://kbin.social/m/kbinMeta/t/29670/kbin-contribution-and-information-for-instance-owners
