Not show folder created by another app when using API: api.dropboxapi.com/2/files/list_folder

There are a few reasons you may not be seeing everything. First, note that if your own app is registered for the "app folder" access type, it will only be able to access the contents of its own app folder, and won't be able to see the app folders of other apps. It's not possible to change the access type on an existing app, so if necessary, you can register another here.

Second, note that you aren't guaranteed to get all of the results back from a single call to /2/files/list_folder. You'll need to check if the returned has_more is true, and call back to /2/files/list_folder/continue with the returned cursor (and repeat with the /2/files/list_folder/continue response as well) to retrieve more entries.