My error was caused by using FB. It is issue described here. Fortunately it was solved with SDK version 17.3.0. So update it now.

Hello, since iOS 18 I have the same problem, when I make longer pauses between speaking, SFSpeechRecognitionResult somehow forgot transcriptions before making pauses. I have found a workaround which I described in StackOverflow post: https://stackoverflow.com/questions/79005416/sfspeechrecognitionresult-discards-previous-transcripts-when-making-long-break/79005417#79005417

You can now use product.priceFormatStyle.currencyCode.