site to site transfer stops after file complete, even if non-empty queue

[MxxCon]

during FXP when transfer is done you should see 2 'transfer complete' messages. but your log shows only 1, which means connection to the other server was lost.
either your firewall or server's closed that idle connection.
try enabling 'send noop during transfer' and/or change idle connection timeout value in your firewall.

also please update your message board profile to include your FlashFXP ID.