Hi there,
I don't know if you still have issues with this, if so, you could try the following:
-Go to C:\Users\<yourusername>\Documents\Mount&Blade Warband and open rgl_config.txt.
-Search (Strg+F) for max_number_of_connections = and replace the number behind the equal sign with 6.
That might help with loading more servers, at least it used to to it for me.
I hope that was helpful