Facebook app marketers: Make sure your apps are set to Live Mode
Starting October 23, apps set to Development Mode will not be able to access certain levels of data connected to users interacting with the app's integrations (such as Pages or ad account information).
24 Sep 2019 ... Facebook app marketers: Make sure your apps are set to Live Mode ... have completed App Review for the permissions and features your app requires, you ... Facebook has made a number of changes to its app policies since ...