A supplemental macOS Catalina update landed Wednesday. It aims to fix some of the issues that came along with the recent 10.15.4 update.
macOS Catalina 10.15.4 Issues Resolved
The notes accompanying the upgrade said that it fixes the problem of users running macOS Catalina 10.15.4 being unable to participate in FaceTime calls with those using devices still running iOS 9.3.6 and earlier or OS X El Capitan 10.11.6 and earlier. Furthermore, Office 365 users should no longer receive repeated password prompts. In terms of hardware, the problem of 2020 MacBook Airs hanging in Setup Assistant or when disconnecting and reconnecting a 4K or 5K external display has been fixed. Instances of Mac USB-C ports becoming unresponsive have also been resolved.
To install the upgrade manually tap the Apple icon on the top left corner of your screen > system preferences > update now. The update requires users to restart their Mac. Users with automatic upgrades do not need to follow these steps.