Make sure the you click the Lobby tab in the main Winamax lobby window. And then try everything again. That should work. On Winamax, the tournament lobbies are built-into the main lobby. All tables should work if you make sure that you click back to the main lobby tab within the Winamax lobby window:
www.imgur.com/a/biDJd3e
The problem looks like that when you open or click over to a tournament lobby, it changes the titlebar text of the whole lobby window. When SaT is running, if it sees the word "Lobby" once it should remember it until the program is closed. When you re-open SaT new again it will reset and look for the title "Lobby" again.
This will be fixed in the next version.