Cant connect to some gmod servers

OK heres the thing. There are some gmod servers(gmod 10 btw) i can join i press connect i go in and i play and its all good. But most of the servers on the server list i cant join as in i press connect and i see the loading screen for one second then im back on the main menu without doing a thing.
No warning or error.

Bumb and if its already been answered can i have a link pls?