Our app uses RecurringApplicationCharge. When our customer confirms a charge in Shopify, he/she is redirected back to our app. In most cases the url contains charge_id. So the url is decorated_return_url. However in some cases it doesn't contain charge_id even though the charge was confirmed in Shopify and is active. Why is that?
Thanks for sharing all of those details, example docs and outlining a functionality you feel isn't working as expected. There are known cases where it is expected for a charge_id not to carry over in a return_url, however there have been a few similar reports that our teams are tracking at the moment. For next steps, our suggestion would be to connect with Shopify Partner Support to share a few examples.
Generally an investigation requires some specific details such as an x-request-id and date response header, request body, full endpoint, and response body showing the behavior. In the case of data that was returned via the Admin directly, we instead suggest requesting collaborator permissions on an affected store, and documenting a url/timeframe.
Please feel free to share a link to this post should whomever you work with need to review as context - Best!