I coded my mobile app using Cursor and have recently been building and submitting for TestFlight using XCode version 16.1. I am testing using my Iphone via the downloaded build from TestFlight. My onboarding flow goes smoothly, but when I reach the checkout page I receive an error that says "Error Loading Products". When I select "OK" and then try to click one of my available products I receive another error that says "Products Not Available". I am signed out of my main Apple ID and signed into a Sandbox user that is valid. I have all of my application agreements signed and valid. I believe everything is configured properly, but I have been receiving purchase errors for the past week with no progress.
I had one semi-successful attempt where the Apple payment screen appeared, but have not had that since. Even on that attempt, there was a payment failure afterwards as well.
Any help would be greatly appreciated. I would like to get a build submitted for app store review as soon as possible.
I've attached screenshots to this ticket showing the error messages in more detail.