Apple recently released macOS Sonoma 14.4, which introduces some new features as well as security patches. However, the latest update to the Mac operating system has also been causing issues for some users. More specifically, macOS 14.4 seems to break USB hub support for some external monitors.

macOS bug affects USB hub for external monitors

As reported by Himanshu Arora on Tech-Issues Today, there are multiple reports of Mac users having issues with their external monitors after updating their machines to macOS Sonoma 14.4. The update breaks the USB hub functionality of some displays, causing peripherals such as mouse and keyboard connected to the external monitor to no longer work.

The website lists multiple posts from Reddit, Apple Community and Dell forums with users complaining about the macOS 14.4 update. “After updating, my keyboard and mouse are no longer being detected on my MacBook. Before updating, it was working fine,” said the owner of a Gigabyte M34WQ display.

“I have the same issue with my MacBook Pro M2 Max 64GB RAM and monitor Dell U3219Q; none of the USB peripherals connected to the Monitor’s USB hub work,” another Mac user complained. “On the contrary, all peripherals work fine when I attach a Windows computer to the Dell Monitor,” the same person added.

Apple is yet to acknowledge the issue or release a software update to fix the bug. In the meantime, users have found some workarounds. If you’ve been affected by the bug, here’s what you can try to fix it:

• Open the System Preferences app
• Go to the Privacy & Security menu
• Look for “Allow accessories to connect” and change it to “Ask every time“
• Turn off and unplug your monitor
• Reboot your Mac
• Turn on the monitor and plug it into your Mac

Have you been affected by the bug that breaks USB hub support for some external monitors in macOS? Let us know in the comments section below.

Source: 9to5mac