pgAdmin takes a look at the database when you open it and then you are working with that snapshot. Any changes made will only be visible to pgAdmin after you do a "refresh". This is a right-click menu option on most objects in the object tree.
So even while you know you have changed the table and the changes are in the database (you can use the SQL editor to verify that), pgAdmin doesn't - an object tree refresh (in your case on your table users
) fixes that.