A root certificate used to sign Faithlife's SSL certificates expired on September 30th. (For technical details, see https://scotthelme.co.uk/lets-encrypt-old-root-expiration/
.) Faithlife's SSL certificates are all signed with a new, valid root CA, but the presence of the old CA is causing some devices (primarily Android, but also older macOS) to fail to connect to Faithlife servers.
* Logos Bible Software (Android) - Sync
* Bible Engagement Project app (Android) - Sync
* Proclaim Remote (Android) - All functionality
* Proclaim (macOS <= 10.11) - Sync