Why is Celsius (℃) printed as ' Unknown ' when taking a QR Barcode with a 'Zebra' scanner?

Question

I am using a QR barcode containing a long string in "," (comma) units. Celsius (°C) is the problem.

Why is Celsius (℃) printed as ' Ž ' or ' ℃ ' when taking a QR Bacode with a 'Zebra' scanner?

problem is "+100℃"

If UTF-8 is selected, it is deleted. ( +100 )

I don't know what's wrong.

Day 6 I thought it was a simple job, but. It is becoming the main project.

i try is Country Code Pages - UTF-8, Non-CJK UTF-8 Emulation Output

printer - ZD421 scanner - DS4308

string qrcode = "+100℃"; 
string zplCommand = "^XA^MD20^MTT^PW550^LL350^LS10"; 
zplCommand += "^FO100,030^BQN,3,3^FD " + qrcode + "^FS"; 
zplCommand += "^XZ"; 

and print code is (param is zplCommand) 'RawPrinterHelper -> byte[] buffer = Encoding.UTF8.GetBytes(szZplCode);

Answer 1

(This is a translated text.) Using the information and expected parts of those who helped with 'comment'. I've tried several things.

https://supportcommunity.zebra.com/s/article/Printing-with-International-Characters?

Use '^CI27' throughout the article, 'escape' processing.

thank you

before "^XA^MD20^MTT^PW550^LL350^LS10";
after "^XA^CI27^MD20^MTT^PW550^LL350^LS10";