byobu é apenas um wrapper em torno do tmux, que é responsável pelo comportamento que você está vendo. O tmux está tentando traduzir "chaves" na seqüência de caracteres que o xterm codifica chaves especiais modificadas. No manual, isso está documentado:
xterm-keys [on | off]
If this option is set, tmux will generate xterm(1) -style
function key sequences; these have a number included to
indicate modifiers such as Shift, Alt or Ctrl. The
default is off.
embora em versões novas / recentes, o padrão é em . Isso expôs um problema, visto nesta mensagem de confirmação:
commit d52f579fd5e7fd21d7dcf837780cbf98498b10ce
Author: nicm <nicm>
Date: Sun May 7 21:25:59 2017 +0000
Up to now, tmux sees 33[OA as M-Up and since we turned on
xterm-keys by default, generates 3[1;3A instead of
33[OA. Unfortunately this confuses vi, which doesn't understand
xterm keys and now sees Escape+Up pressed within escape-time as Escape
followed by A.
The issue doesn't happen in xterm itself because it gets the keys from X
and can distinguish between a genuine M-Up and Escape+Up.
Because xterm can, tmux can too: xterm will give us 3[1;3A (that is,
kUP3) for a real M-Up and 33OA for Escape+Up - in fact, we can be
sure any 3 preceding an xterm key is a real Escape key press because
Meta would be part of the xterm key instead of a separate 3.
So change tmux to recognise both sequences as M-Up for its own purposes,
but generate the xterm version of M-Up only if it originally received
the xterm version from the terminal.
This means we will return to sending 33OA instead of the xterm key
for terminals that do not support xterm keys themselves, but there is no
practical way around this because they do not allow us to distinguish
between Escape+Up and M-Up. xterm style escape sequences are now the de
facto standard for these keys in any case.
Problem reported by jsing@ and subsequently by Cecile Tonglet in GitHub
issue 907.