Universal Control stopped working

Unfortunately the screen mirroring trick stopped working.

However, I've had a really good string of luck with Universal Control working, I definitely think it has to do with other accounts not being logged in. My family hasn't used the desktop Mac mini for quite some time, so there haven't been any other users on the system. Universal Control has worked perfectly.

I think - for me at least - it stops working when other users are logged in.

I've had the same problem as OP, and the update seems to have been the cause of universal control breaking for me. I used to be able to simply add my screen in Display Preferences and it would always work.

My only options at the moment are either extending or mirroring my screen, rather than simply having my mouse move across on the iPad home screen. The Universal Control options suggest that you can simply move your cursor to the edge of the screen for Universal Control to work, however that doesn't work for me.

I'm using MacBook Pro with a 27" display.

Universal control was always spotty for me, appearing to only work at random times. Recently, it completely quit permanently. Nothing I do will bring it back, I have tried everything to fix it. I’m out of ideas. This is really irritating.

I have exactly the same problem. When UC first came out I could get it to work on my main Mac user account, but not in a second Mac user account (with same iCloud account). I spoke to Apple and we agreed it was probably because it was still in Beta. Recently, after the Mac 12.4 and the iPad 15.5 updates (now out of Beta), it started to work in both accounts. Now, in the past few days it will not work at all in either accounts. I am finding this very frustrating, it seems to be very flakey software. It could be a very useful tool for me if it consistently worked. I am also looking for ideas for a fix.

Sorry to be clearer, I go Add Display, Extend to Mac mini via Airplay, then disconnect and it seems to work. Maybe try using Airplay rather than Sidecar if possible?

Universal control was working fine for me until I updated my 2018 iPad pro to 15.5.

I checked my settings and everything seems fine.

My iMac is a bit on the older side, late 2015, but was working up until the update. Sidecar still works, not sure if that's related or not.

Anyone else experience this?

This is where I am at too. Most if everyone I’ve talked to about this from apple and friends in the know is it’s in beta or it should just work. It’s very irritating when it had already worked before !

After spending 10+ hours on the phone with Apple, they told me to re-install the OS. I reinstalled it on 12.4 which worked! - However, after updating to 12.5 it stopped working again. Apple told me to re-install the OS again (I just installed it a week ago!), this helped briefly but a few hours later it stopped working again. I spent a few more hours with Apple, they said a few people are having this issue and they will call me back tomorrow.

Sure enough, it stopped working today. The Menu Bar Displays menu doesn't show the iPad anymore - it used to, and I could link to it. Today, nope.

What's weird is that Handoff still works b/n the Mac Mini and the iPad (e.g. I can bring up the Safari window on my iPad that I'm viewing on my Mac). iCloud Copy and Paste still works between the two computers. And Sidecar still between the iPad and Mac.

But not Universal Control.

This is very frustrating!

When you say "extend the MBP display to my Mac mini via airplay" what do you mean? Do you mean selecting your iPad from the "Add Display" drop-down ("Mirror or Extend to")? I thought that was Sidecar - that works for me even when Universal Control doesn't work.

Same for me. Universal control is awesome when it works, but it randomly works for a number of seconds, then stops. I've done all the suggested changes about Firewall, Bluetooth, hand-off, etc., but it is continually randomly failing. Both my Macs are M1 (M1 mini, and M1-Studio) on the latest version of Ventura. It's an awesome feature, but frustrating when it can only be used for a few seconds at a time

I think something finally worked with the update and I now have the additional option to link my keyboard and mouse. All good now! Thanks!

That's a cool trick! I had no idea. I'll keep an eye out on this and report back.

I just tried that and it didn't work. I can extend the display via Sidecar and it works fine. After I disable it, Universal Control still doesn't work. Very frustrating!

Hah! Awesome! Mine tends to drop off at least once a day, so it was a fair bit of trial and error to find this fix, so I am stoked it worked for you too!