Fortunately, I found how to turn it off and (in the GUI version at least) all my transfers are successful. On the contrary, in batch mode from a script file, even after settingServer unexpectedly closed network connection.
-rawsettings SendBuf=0appended to the
opencommand, the connection will "unexpectedly close" on files larger than a few megabytes.
SendBuf=0completely turn off the feature as the GUI checkbox does?