I'm using Ubuntu 18.04 LTS version. Usually, I will have 3-4 terminals opened at any instant for doing several things. The problem is that, if I leave a terminal open and idle for a few minutes then that terminal will be frozen. That is, it will no longer respond to commands or any action. I can't type anything in that terminal window nor copy/paste anything. I have to close that window and then re-open for continuing my activity.
This is happening frequently and it is really annoying. can anyone suggest what is causing this and How can we fix this?
P.S : I'm not using the computer over ssh.