AVSpeechSynthesizer read Mandarin as Cantonese(iOS 26 beta 3))

In iOS 26, AVSpeechSynthesizer read Mandarin into Cantonese pronunciation. No matter how you set the language, and change the settings of my phone system, it doesn't work.

 let utterance = AVSpeechUtterance(string: "你好啊")
//let voice = AVSpeechSynthesisVoice(language: "zh-CN") // not work
 let voice = AVSpeechSynthesisVoice(language: "zh-Hans") // not work too
utterance.voice = voice
et synth = AVSpeechSynthesizer()
synth.speak(utterance)