Sonoma 14.4 Breaks USB-C Monitor with Hubs?

[tzchang]

Just upgraded to Sonoma 14.4 for both my M2 Pro MBP16 and Mac Mini... Both connected directly to a Dell U3419W via USB-C. I have my external keyboard/mouse and other USB peripheral devices connected to the U3419W as downstream.

After upgrade to 14.4, the monitor still works... can be recognized and display correctly. However, all the USB devices connected to the U3419W are gone... Nothing is recognized. If I unplug the U3419W and plug it into a Thunderbolt dock and then connect the Thunderbolt dock to Mac, then all the downstream devices works.

I also saw a few other cases from other forums.
https://discussions.apple.com/thread/255518397?sortBy=best
https://www.reddit.com/r/MacOS/comments/1b9volo
Apparently, Sonoma 14.4 breaks the USB-C monitor with hubs......

 

[FNH15]

Just upgraded to Sonoma 14.4 for both my M2 Pro MBP16 and Mac Mini... Both connected directly to a Dell U3419W via USB-C. I have my external keyboard/mouse and other USB peripheral devices connected to the U3419W as downstream.

After upgrade to 14.4, the monitor still works... can be recognized and display correctly. However, all the USB devices connected to the U3419W are gone... Nothing is recognized. If I unplug the U3419W and plug it into a Thunderbolt dock and then connect the Thunderbolt dock to Mac, then all the downstream devices works.

I also saw a few other cases from other forums.
https://discussions.apple.com/thread/255518397?sortBy=best
https://www.reddit.com/r/MacOS/comments/1b9volo
Apparently, Sonoma 14.4 breaks the USB-C monitor with hubs......

Have you tried updating the firmware?

U3419W Firmware Update | Driver Details | Dell US

 

[vanc]

It's quite strange. I also connected my 16" MBP with M1 Pro with two different Dell monitors. One UP2720Q at home and one U3224KB at work. All downstream ports still work after upgrade.

You may check the System Information app and see if the Dell builtin USB hub is still there. For me on UP2720Q,

 

[mjodotcom]

I just came to this forum to report the exact same issue - 14.4 definitely breaks USB hub monitor functionality. Things worked without a hitch until my work MBP upgraded to 14.4 and now no devices are detected. On my personal MBP that is still on 14.3 everything is detected without issue. Clearly a OS related problem. Others have also reported this on reddit (see below). Anyone figure out a workaround?

https://www.reddit.com/r/MacOS/comments/1b9volo