When I added a regular user in Alpine Linux which is a container in LXD running on Debian Bookworm, no matter what I did, it would not use BASH. Everything was changed correctly. I changed it using chsh, I modified /etc/passwd...anytime I su - user, it would always use ash. I know bash is installed since I could enter bash and it would change shells.
Solution:
create a .profile file in $HOME
vi ~/.profile
In your .profile, add the following:
if [ -n "$BASH_VERSION" ]; then
# include .bashrc if it exists
if [ -f "$HOME/.bashrc" ]; then
. "$HOME/.bashrc"
fi
fi
Exit and log in again, and you should be using bash.
