A problem has developed on one of my systems in which terminal output is getting truncated. When I login via SSH for instance and I run For ls -l command only 3 or 4 lines are shown, then the screen hangs.  When I connect to the terminal directly, ie via VNC the same  happens.However when I connect via wetty for instance  everything is fine.Any ideas of what the cause could be, or how to diagnose what is happening?
How to diagnose problem of terminal output truncation
terminal