Computing a hash is a math operation on binary data. It produces a fixed size array of bytes, depending on the algorithm. It doesn’t produce characters.
What you’re seeing is encoded output. The SQL utility you’re using has decided to output the byte array as some form of Unicode. Instead, you need to change the output encoding of your SQL so you can view the data in a way that makes sense to you.
If you’re using Microsoft TSQL, you could look at a function like
master.sys.fn_varbintohexstr to output the data in hexadecimal.