Universal Control Became Intermittent With Recent MacOS Update

Same here. Universal Control was rock-solid for months, then seemed to degrade when my M1 MacBook Pro moved to Sonoma over a month ago. I previously used a 2019 iMac i5 on OS 13 for keyboard and trackpad. That has since changed to an M2 Mac Mini on Sonoma, and the frequency of the disconnects seemed to get worse. I'd say that a disconnect every 10 minutes or less is the norm now. Reliably unstable. Super annoying with the potential to cause harm, as the Mac Mini will recapture focus with no warning and start feeding keystrokes to the last app active on the Mini, instead of the app I am actively using on the MBP.

My recovery is to keep System Settings > Display open on the Mac Mini. This speeds up the process of the Mini rediscovering the MBP.

Further update: sometimes instead of the focus returning to the Mini, the keyboard and trackpad of the Mini will become completely unresponsive for 10-15 seconds, with no cursor movement visible on either machine in response to Mini trackpad activity. The MBP keyboard and trackpad will work during this time, but the MBP cursor won't be able to traverse to the Mini display. Activity Monitor on the Mini does not stop refreshing and doesn't show any strange resource consumption patterns, although I am not able to interact with the Mini until it decides to recognize its input devices again.

I have rebooted multiple times, logged out of Apple ID on both Mac's, Turned off Universal Controls in the Display Advanced Tab, rebooted. Then re-enabled it, rebooted, and still nothing.

It use to stop working when I had Youtube up in a browser or I was in the Music App playing music.

I wish this could get resolved as I did enjoy the convenience of only having one set of keyboard and mouse on my desk.

A +1 from me. Universal Control was working reliably until I installed macOS 14.3. It disconnects and refuses to connect regularly (each connected session never lasts longer than 10 minutes).

Occasionally it will reconnect when I move my cursor to the frame of the desktop, but usually I need to sleep/wake one of the involved machines to get it connecting again.

Great to hear this worked for you. It did not work for me. My Mac Mini and MacBook Pro are both on 14.4.1, but the Apple ID sign-out, reboots, and sign-in had no effect I could observe on the intermittent loss of Universal Control. The release notes for 14.4.1 had no mention of a fix for UC.

I'm running on Sonoma 14.4.1 (23E224) from a Macbook Pro 16" 2023 (Apple M2 Pro chip) and an iMac 24" 2021 (Apple M1 chip). All software up-to-date and I have wifi enabled but not connected to any network since I'm forcing the connection through ethernet (which works much faster indeed).

For me, it disconnects suddenly but I make it back just leaving the "System Settings > Display" tab opened on both machines. Looks like opening those screens trigger some kind of scanning/detection that makes things connect again. Annoying but usable.

Praying for a fix and hope this helps somebody.

Reading all the posts and with the same issue from Mac Pro to M1 iPad Pro, Apple! WHATS THE FIX?

FWIW: I updated both the MacBook Pro and the Mac Mini to MacOS Sonoma 14.4 today. The intermittent Universal Control behavior did not change. I keep the Displays panel of System Settings active on both devices. They always update instantly when the loss of sync occurs, with the nearby device disappearing from the screen topology view. I've learned to react to that when it hits my peripheral vision, just like Pavlov's dog--hardly even breaks my train of thought any more. Clicking one or the other of those Display panels to bring it into focus minimizes the interruption, redrawing the screen topology to include the nearby device. Typically I find that the MBP is quicker to discover the Mini after losing sync, rediscovering it within half a second. The Mac Mini is sometimes slower, taking 2 or 3 seconds to rediscover the MBP.

I'm updated on everything, ever once in a while after a reboot Universal Control will work, but once it stops working not matter how any times I reboot, it's completely random at when it will work again.

I have check the firewall settings, options allow incoming connection for Universal Controls on both systems. but again it's not consistently working. Ive even turned off the fire wall for a while and still it's completely random when Universal Controls work.

But one thing that I think I figured out is when it stops working.

100% if I launch Music app, universal controls stops working. The other thing that I noticed is when UC is working and I take a Safari window and I drag it towards the second monitor, before I even let go, the moment the safari browser window goes pass the screen UC stops working.

From that point on, reboots, turn off and on the firewall, etc it's never consistent on when I can get UC back up and running.

Another thing I noticed is when it's working/reconnected, the arrangement of my screen is back to default. Where the screens are at the same level.

But physically it's not. The second system I do not have the monitor on a stand so it's sitting right on the desk.

So I have to keep resetting that.

And for me, it's definitely related to the Music App. As a test I rebooted everything, but I did not launch my music app after the rebooting and logging in.

UC was working, but arrangement of the screen is off. And the moment I set the arrangement of the screen, I checked and UC is work. The Moment I launched the Music app, it stopped.

Universal Control has been intermittent for me since it started. It appears as though my MBP is somehow signing out of my iCloud account without telling me. The only way I can fix this is to log out of iCloud and then log back in, which fixes it every time. The problem is that this is inconvenient, as I need to go through quite a process to get everything back online. It's not just a logout and then log back in. I wish Apple would own this and tell us what is happening and if they are working on it. This also happens with my iMac. Universal Control and Continuity Camera are fantastic features but the intermittency is unacceptable.