I’m more interested in how you made them appear! Yours is the only indication I’ve found anywhere that setting up Twitter in Online Accounts actually achieves anything at all. (Online accounts - Twitter)
I was wondering if I’ve just managed to miss the notifications but the GNOME 3 notification thingy at the bottom is supposed to let you view notifications that you’ve missed, isn’t it? Are the notifications you see available to look at later if you don’t acknowledge them when they appear?