A long time ago we implemented in app purchases in our application through RevenueCat and it was working fine until we got this issue from users for some reason:
‘There was a problem with the App Store., readable_error_code: STORE_PROBLEM, userCancelled: false, underlyingErrorMessage: An unknown error occurred, readableErrorCode: STORE_PROBLEM’
It appears in logs when users are trying to press "subscription button" buy.
We didn’t touch any implementation of this and configuration in App Store Connect so it’s just happening for some reasons of App Store?
Also, maybe this information will be helpful - previous build was rejected in first attempt because of ‘cannot locate iAP’ after build was approved but in this build appeared this issue.
Looking forward for your reply!