To reply to my own post: the problem I was experiencing was resolved in much the same way as for josessolmaximo: I explained that I thought there might be a problem on AppReview's side since the IAP process worked perfectly against the sandbox, and I quoted this thread. App Review then asked me to provide a video demonstrating the full IAP process running against the sandbox on the latest version of iOS/iPadOS. After receiving the video the app was taken back into review and subsequently approved.

Interesting. This is currently happening to me: it works perfectly in development against the sandbox and when using TestFlight but consistently fails in review. I raised a TSI for it and was told the same as you, that SKProductsRequest was returning no products. A bug was raised for the App Store Server engineers to investigate, but the problem is still present a week later. Unfortunately App Review appear to be ignoring anything I put in the review notes or send to them via the submission messaging system. I'm literally at the point of abandoning the IAP and going for a paid app because there doesn't seem to be any other way out.

Same thing here as well. It shows up when I build a project that isn't set up to use Xcode Cloud.

Thank you for posting Apple's response.This actually raises another question: I need to pass back an array of data, and using multiple parameters would be very cumbersome. At the moment I keep a reference to the audio unit after creating it in createAudioUnitWithComponentDescription so I can call a method on it to retrieve the data; I wonder whether doing this is problematic in some way?

Thank you, I'd be most interested to hear what the recommended way to deal with this issue is.

I'm also experimenting with this at the moment.I have a GCD dispatch queue and timer running in the audio unit (not the view controller) to poll the data generated by the render loop: this works OK. The problems come in getting the view controller to update: if I post a notification on the main queue via dispatch_async then it works, but if I have multiple instances of the AU running (on iOS) they all pick up the notification.

I'm seeing exactly the same thing: nothing since 10th January in Sales & Trends when displaying the results for the last 30 days, but figures do appear for 11th January when displaying the results for the last month.