check

locale
cat /etc/default/locale
cat /etc/locale.gen
cat /etc/locale.conf
echo $LANG

printf "\n--- locale env ---\n"; locale; \
printf "\n--- generated locales ---\n"; locale -a; \
printf "\n--- /etc/default/locale ---\n"; cat /etc/default/locale 2>/dev/null; \
printf "\n--- /etc/locale.conf ---\n"; cat /etc/locale.conf 2>/dev/null; \
printf "\n--- environment ---\n"; echo "LANG=$LANG"; echo "LC_ALL=$LC_ALL"

generate and set default locale

dpkg-reconfigure locales

sudo nano /etc/locale.gen              # check if "en_US.UTF-8 UTF-8" is uncommmented

sudo locale-gen                        # generate locales

sudo update-locale LANG=en_US.UTF-8 LC_ALL=en_US.UTF-8
cat /etc/default/locale

└─[$] locale
LANG=
LANGUAGE=
LC_CTYPE="POSIX"
LC_NUMERIC="POSIX"
LC_TIME="POSIX"
LC_COLLATE="POSIX"
LC_MONETARY="POSIX"
LC_MESSAGES="POSIX"
LC_PAPER="POSIX"
LC_NAME="POSIX"
LC_ADDRESS="POSIX"
LC_TELEPHONE="POSIX"
LC_MEASUREMENT="POSIX"
LC_IDENTIFICATION="POSIX"
LC_ALL=

Fix

sudo nano /etc/ssh/sshd_config
UsePAM yes