The manga that you have marked "read" or "reading" probably have not been updated so you haven't got any notifications. If you want to look at the manga that has just been uploaded/updated than click on your preferred genre and click "Sort by: Update date"
I don't know why there isn't any manga updates for two days I mean I usually get notification but I didn't get it for two days.
Anyone know whyyy? ╥﹏╥