"Model" selector not working in content sync.

[#1]

I'm trying to use content sync mechanism to generate JSON's for my webpages in a zip file which will be ultimately used in mobile app. below is the app configuration i'm using to create the jsons zip. the issue i am facing is, if i use "Model" as selector then it is throwing errors in the json files. whereas when i do model.json (../en.model.json) in the page url it is returning complete page json.  I've also tried other selectors like Infinity and caas, but they are not giving complete JSON of content fragment rather just returns the path as value. trying to find if there's anything to configure in OSGi or write custom code to work it out.

App-Config:

     path: /content/sample/en

     type: pages

     selector: model

     deep: true

     extension: json

     targetRootDirectory: www

[#2]

Are you following any online AEM doc to perform this use case - can you point the community there to see if this is reproducible.

[#3]

I'm following this article Mobile with Content Sync

[#4]

If you are following this Adobe DOC and not getting the results as documented - there could be a bug. I would open a support ticket and refer to this doc and say that its not working as expected.