me too having the same.
Normal but no alert and now i check the software center and find updates are there waiting for me

did not see a physical banner popup but I'm not at the computer every second.
but I had the tray indicator turn blue so I knew an update was there.

I do not know if they did away with the popup or not/cannot answer. Even that times out a 5 seconds or less so is there a chance you missed it?

I get update notifications on Solus Gnome, if that helps.

Hmm, maybe something going wrong with our solus-update-checker script (part of the Software Center).

    Staudey should solus-update-checker run at startup?
    if i launch it in terminal i get the notification, but it doesent stay long