Byobu

Byobu is a GPLv3 open source text-based window manager and terminal multiplexer. It allows for the execution of multiple shells in one terminal.

to load bash_profile

in /usr/local/bin/byobu-shell  or /usr/bin/byobu-shell

there is one lile

[ -n "$SHELL" -a -x "$SHELL" ] && exec "$SHELL" || exec /bin/bash

changed it to

[ -n "$SHELL" -a -x "$SHELL" ] && exec "$SHELL" --login || exec /bin/bash --login

Reference:
https://byobu.org/index.html

https://help.ubuntu.com/lts/serverguide/byobu.html
http://manpages.ubuntu.com/manpages/eoan/en/man1/byobu.1.html

https://bugs.launchpad.net/byobu/+bug/525552