The computer where less scrolled had
LESS=-r, the other had
From the less man page:
-q or --quiet or --silent
Causes moderately "quiet" operation: the terminal bell is not
rung if an attempt is made to scroll past the end of the file or
before the beginning of the file. If the terminal has a "visual
bell", it is used instead. The bell will be rung on certain
other errors, such as typing an invalid character. The default
is to ring the terminal bell in all such cases.
-X or --no-init
Disables sending the termcap initialization and deinitialization
strings to the terminal. This is sometimes desirable if the
deinitialization string does something unnecessary, like clear‐
ing the screen.
-X option prevented scrolling all together and the
-q option caused the pager to enter a non scrollable state when scrolling past the beginning or end of file.
My options are now