When creating an app on Instagram Platform, it starts in Sandbox mode, to allow the users/developers to test the API before submitting it for review and go live.
Sandbox mode is meant for development, thus coming with some restrictions. Data is restricted to sandbox users and the 20 most recent media from each sandbox user. This means that, only photos that belong to the sandbox user will be returned, so if you set your feed type to Tag or Location, only sandbox user's photos be shown.
If you want to display photos with a specific Tag or Location, uploaded by any public Instagram user, you have to get out of Sandbox mode and go Live with your Instagram app. More details about the limitations and API behavior in Sandbox mode HERE.
For going Live with your Instagram app, you can follow Instagram Platform documentation HERE.