Copy & pasting from my comment on Ticket #19711 (resize clears the screen). I guess it should really be a new ticket:
New to TeraTerm (4.65), so I'm not sure if this change is the cause, but I think this feature needs to be better implemented. When I make the window smaller, it clips the content to the new resized area, and not just the current view but the whole buffer. So if the window was 80 char wide, and you make it 30 characters wide, anything that was right of the 30 characters mark is lost.
The view/output, after being rendered, should not be modified. If you resize the window, you only see a subset of the view, but if you make it bigger, you see again. There could be a horizontal scrollbar option that a user can toggle, if wants to see whats off the screen to the right/left. I prefer to be no horizontal bar, but I'm sure someone will request one, so a toggle would be good. In SecureCRT , this is the behaviour, where the view stays. If you make it smaller, you just can't see it, but if you make the window larger again, etc., its still there.