Check that you're subscribed to whatever you're looking for updates on. You might not be because they're not in your lists. BUT I suggest not editing your lists right now as the site is more unstable than usual, especially these last few days.
More info in link:
https://www.mangago.me/home/mangatopic/21255174/
But also, in Suujin's initial FAQ, it seems the user data or something isn't really synced? I don't understand all this technical stuff, but it seems notifications aren't really working after the site crash.

For some reason all of my bookmarks are not being updated with new chapters in my notifications and so I lost all of my readings. Though for some reason only 1 is being updated, and for my other bookmarks they’re still active but I can’t seem to get updates for new chapters. Please helppp ┗( T﹏T )┛