+xI think you are wrong, the airports shown in the tab are "attached" to the route.
If you want to have some airports always shown in the tab you could create a route, add the airports you use frequently and the save the route.
Next time you open the saved route you will have the airports in the tab and from there you could modify the route by adding or deleting waypoints and airports.
Thank you very much. I was Complete wrong. I thought the Airports listet in the right Airport Button are some kind of favourites which you can access very quick.
Now knowing that they belong to the actual route all this makes sense.
Nice greetings