Hi alay,
When you get the disconnect problem, you will get the number of the connection. As you descripted, the _104, _106 .. etc.
Please try connect the server again and again, you will get the number again and again.
If you get increased number list, for example _104,_106,_111,_115... that means network is not fast enough for the big traffic, and server may close the expired connection.
If you the number do not always increase, for example _104,_106,_103,_105,_102... that means the server is rested by an unknown reason.
Regards,
ken