This happens because you have a specific App Type on Facebook. Each labeled types give access to different permissions. Consumer will let you access your profile, while Business would only let you access your page. JIG needs an app that does both at the same time (unfortunately they are moving in a direction that will make the workflow harder in the future by forcing you to have two separate apps if you want to access both your profile and page). Therefore when setting up the app, you need to choose this type (it's not the default):
If you already have an app, you need to start over.
The permissions currently needed are:
- user_photos - Consumer
- user_posts - Consumer
- user_videos - Consumer
- pages_show_list - Business
- pages_manage_metadata - Business
- pages_read_engagement - Business
When you have no particular App Type you have access to all at once.