BUG #17895: Bug concerning utf-8

The following bug has been logged on the website:

Bug reference: 17895
Logged by: wilferic
Email address: ericwilfried(dot)ettien(at)gmail(dot)com
PostgreSQL version: 15.2
Operating system: Windows 11
Description:

Good afternoon,
I have installed postgresql 15.2.1 on windows 11 and i created database name
like this: my_db_name.
In fact when i created databse with default value utf-8 i received this
error : 'utf-8' codec can't decode byte 0xf4 in position 8: invalid
continuation byte.
So i explored solution and i used this link:
https://stackoverflow.com/questions/45897521/postgresql-utf8-codec-cant-decode-byte-0xe9-in-position-42-invalid-continua.
However this error is the same.
Please i would like to have solution concerning this error.