fix chinese characters display on webpage

I have a custom API on a Linux system that allows to pull some data to another system. In the MySQL table I nicely see the Chinese characters in the name field. However when I pull the data to the other system and display I get to see question marks instead of the Chinese characters. I had this setup before on same system as test environment there I could see the Chinese characters properly. However now the API is in the live environment I get the question marks. The database column in the table is UTF8 unicode. The JSON reply from the API is encoded with JSON_UNESCAPED_UNICODE. And the API has header: header('Content-Type: application/json; charset=utf-8'); The page where I display the name has: <meta charset="utf-8" /> But I guess the problem is in the API or the server where the API is on because if I pull from the test API I can see the Chinese characters. Because this is a live environment I am looking for someone that can help me resolve this through teamviewer, I will provide a SSH terminal directly to the server through teamviewer.