Client is dead when copy larger text file

[mtwtfss 0]

I am doing some work and need to copy large text file, and it will disconnect for a while and get connection back about half a minute.

 

I check the log and it says:

[ Core    ] [2017-12-06T11:23:10] INFO: switch from "Square-PC" to "Square-NB" at 1807,0
[ Core    ] [2017-12-06T11:23:10] INFO: entering screen
[ Core    ] [2017-12-06T11:23:18] NOTE: client "Square-PC" is dead
[ Router  ] [2017-12-06T11:23:18] debug: Error reading from core server: End of file
[ Router  ] [2017-12-06T11:23:18] debug: Terminating core server read loop
[ Core    ] [2017-12-06T11:23:18] DEBUG: active sides: 4
[ Config  ] [2017-12-06T11:23:22] info: Sending log file...

 

Any idea? Thanks!!

 

Here is the full log file:

https://synergy-logs.symless.com/79ee9835e5af0f12ac2a74de623aafd2/logs/12501-2017-12-06T11-23-22.log