Solution 7 - Works only for incomplete server lists
What if you want to play a Strategus Battle or some Siege, and servers 2 and 3 do not appear on your list, but you see all the others?
Refresh the server list until you see some of the servers you normally join regularly. Add them to favorites. Refresh the list over and over and over again. If more servers appear, choose the once of interest and add them to favorites. If refreshing the list does not reveal any more servers right now, but you know there are more out there, try it in some hours or another day again. As soon as you see more servers you think about joining, add them to favorites. Do this until all your favorite servers are safed under favorites.
When you are done, do not scan the internet for servers anymore, but click on the 'Internet' button. A dropdown list will open, allowing you to search in the Local Area Network or among your favorites. Always scan for your favorites from now on.
I don't know why, but the favorite list is always complete when the servers are online and you are connected to the internet, while the internet list tends to be incomplete even after refreshing it serveral times and waiting for several minutes.
Thanks to PUE for suggesting this solution.