terminal won't scroll up

[mahesh]

Hi,

on Ubuntu 18.04.6 LTS, the terminal scrolling behaviour sometimes changes, usually after some kind of impolite interaction with 'less' (eg killing less or a process piped into less).

When this happens, there doesn't seem to be any way to scroll up. The scroll bar is there, but there's no handle. Also the mouse wheel changes behaviour from scrolling the terminal buffer to scrolling the command history (which is usually hooked to up/down arrows on my system).

The shift+up/down/home/end keys just write capital letters to the terminal.

Is there some corruption of the current terminal configuration? Can I read/write that to correct it an open terminal? I've tried messing with the preferences dialog, but it is spartan and has no effect.

Can I reset the terminal to its original config without losing the current buffer contents?

Note: this happens in a newly opened terminal, so not related to buffer size.

Cheers.