Hi, welcome in my club!!!
Facebook announced some changes to our Developer Offerings and some upcoming breaking changes as part of v2.11 of the API. These changes came into effect on 06/02. As a result, the user will still be able to authenticate but will not be able to retrieve any data as for getting page / insights it is now required to use a Page Access Token matching that page.
Error message that you can probably find in logs: This method must be called with a Page Access Token
This is a known issue affecting all version of Web Connectors. Bug ID: QCWPI-742
NOTE: R&D is currently trying to resolve this