So you can enter in the server then get connection lost after 5 10 laps or direct after you join a server ?
The only thing i now that drivers have problem lost connection many times is if they use wifi never seen this problem when drivers is use wired cable not now what happend when drivers use wifi but for some reason they lost connection often.
I think the can be fixed in multiplayer ini file edit this Net Join Timeout="150.00000" // How long to wait (without a response) before a game join will be considered a failure set it at 450.00000 or something i have no wifi so i have not test this maybe some other here can help you with this question