“I then clicked on the single green arrow (execute current query). …!
I think I understand what is happening!
Refreshing Object Browser only has effect on the part of the tree BELOW current selection! to refresh the list of databases the connection itself must be selected. To refresh the list of tables in a database the database must be selected.
In other word: you refresh what is currently selected only! It is made such because if you have lots of very big databases (and/or a slow connection) refreshing everything can take very long time.
Was that the answer that you needed?