Open Terminal and run:
locale
If you see anything like:
LANG=zh_CN.UTF-8
or mixed values (some en, some zh), that’s the problem.
Run:
sudo locale-gen en_US.UTF-8
Then update:
sudo update-localeLANG=en_US.UTF-8LANGUAGE=en_US:en
Run:
sudo dpkg-reconfigure locales
en_US.UTF-8