Apple’s most recent software updates have reportedly broken FaceTime compatibility with older iPhone and iPad models, leaving many users unable to make voice or video calls during the COVID-19 pandemic.
The issue affects devices running iOS 13.4 and macOS 10.15.4 when they attempt to connect with devices running iOS 9.3.5 or iOS 9.3.6 — or vice-versa. There is no fix for now.