How to scroll up and down in sliced "screen" terminal
Try Control+a, then Escape. After that, you should be able to move your cursor around using the arrow keys.
Press Ctrl-a then [ will enter the copy mode, and you can scroll up and down like vim editor.Leave the copy mode by pressing Escape.
Ctrl-a (default prefix) + [: Enter copy mode.
Esc: Quit copy mode.
Within copy mode:
Ctrl-u, Ctrl-d: Page up/down by certain amount of lines while preserving cursor position (default by half of the screen)
Ctrl-b, Ctrl-f: Page up/down by a full screen