I have the same issue. The link provided in the reply doesn't work for me. There is no audio option when I select the hamburger menu. The odd thing is that my Roku premiere + plays Jack Ryan with Atmos with no issue and not having to take any additional steps (i.e. selecting a different audio format from the stream) .
Yeah, just wasted two hours troubleshooting on chat support only to be told "there is an issue with this and the technical team is working on this. Sorry for the inconvenience and please close the chat window."