I have this same problem. Was updating via the XML updates.
I'm able to retrieve price point ids and such.
But, when I schedule a price update looking almost exactly like the example at the bottom of the page https://developer.apple.com/documentation/appstoreconnectapi/app_store/in-app_purchase/managing_in-app_purchases, with the in_app_purchase id and price tier ids changed, it just returns an Error 500. No Info on whats wrong.
I suspect my problem is with that $(price-id} and $(price-id-1} thats listed in the example. But I can't find ANYWHERE that says what those should be. I've been assuming they are just unique ids for this message, but is there something they should be instead?
knabours
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution
From
San Francisco, CA