Thank you for your reply. I found the new PingFang font file on iOS 18.0 using the CoreText APIs, but its format seems to have changed and is not a regular ttc file. I can’t load it properly using stb_truetype. I copied this font file to my mac, and I can't open it with Font.app either, it says it doesn't contain installable fonts. How can I load this font? We are using stb_truetype to parse the font file.

Not yet. And I have another forum that no one has replied to yet, https://developer.apple.com/forums/thread/759219. Maybe Apple doesn't want us to parse the new font files directly anymore. So I've changed my solution to using native fonts.

Yeah I found that too, but Apple doesn't provide any documentation on hvgl tables. So I switched my font rendering solution and stopped parsing the font files. Thanks for the reply.