Chinese character turns into �� or @@ or just nothing [closed]

For example:

In run and debug:

In terminal:

When I input any Chinese, the debugging interface will show that the value of str1 is �� or @@ or just nothing, and it's a little unstable (but � is quite common).

However, in this situation:

The expression is str1="\255\346��", but the output shows normally.

In run and debug:

In terminal:

What I have tried：

1. select encoding and reopen with GBK
2. open settings-Text Editor-Files-Encoding and select UTF-8
3. turn on Auto Guess Encoding
4. using wstring and wcin and wcout
5. type chcp 65001 in the terminal
6. edit my launch.json and change the environment's "[]", making it use UTF-8
7. In Windows's language settings, turn on Beta version: Provide global language support using Unicode UTF-8

I hope that I can maintain consistency between the value and the output, and I can cin and cout Chinese characters normally, without using wstring.