BUG #15543: PostgreSQL insert question marks instead of unicode characters

The following bug has been logged on the website:

Bug reference: 15543
Logged by: Hayley Sui
Email address: b3.sui15@gmail.com
PostgreSQL version: 10.6
Operating system: mac os
Description:

When installing Postgres, I set the LOCALE to "zh_CN.UTF-8". When I tried to
create table and insert Chinese characters, they turned into question
marks. Then I also tried to set the "client_encoding" to "GBK", it still
didn't work.

Postgres is amazing, and I really want to apply it to our analysis work~
Please do tell me how to fix this! Thanks a lot~