I kept ssh connection alive following this post: Mobaxterm: how to prevent ssh session from exiting?
I managed to keep ssh connection alive but sftp connection on the left panel keeps disconnecting after a certain time while ssh is still alive and I have to every time reconnect the sftp. Sometimes, reconnect button on the left panel doesn't even work and I have to exit the shell and restart the ssh session again. What I want to achieve here is to keep the sftp connection (graphical browser on the left panel) alive in addition to ssh. Thanks.