Hi Simon, within the Commcare documentation it states that metadata does not change. See the highlighted text in picture below:
and here is the page link:
https://confluence.dimagi.com/display/commcarepublic/Data+Cleaning%3A+Clean+Case+Data
If you follow this link below you will see that the app_id is part of the meta data.
https://confluence.dimagi.com/display/commcarepublic/Metadata+Glossary
This is specific to cases only, when a case is edited in Commcare HQ it creates a new form for that case. This updated form app_id is then set to NULL. Which is a problem with the API because when we pull the form data from the API for a specific app_id it doesnt pull through the updates that were made in Commmcare HQ.
Was it intended that the app_id is NULL when updating through Commcare HQ as it is part of the meta data?