Chinese character encoding result incorrect

[an9xyz]

Example:
你好，我叫凯文。
Expected:
[19526, 254, 25001, 121, 171, 120, 234, 22755, 239, 20998, 104, 49035, 107, 23877, 229, 16764]
Actual:
[8423, 8423, 8423, 8423, 8423, 8423, 8423, 8423, 8423, 8423, 8423, 8423, 8423, 8423, 8423, 8423, 8423, 8423, 8423, 8423, 8423, 8423, 8423, 8423]

[xixixi2000]

yes, too many 8423