SideCar unstable in Monterey

After update to latest Monterey 12.3 (Mac mini M1) and iPadOS 15.4 (iPad Pro 9.7") I couldn't see Sidecar / Screen Mirroring via USB, though iPad was recognized just fine on Mac. I had a few chats with support, glad I didn't proceeded with reinstalling macOS (as they suggested after a few other options weren't successful).

Solution, that came to my mind and did the trick was actually very simple:

>> Reseting trusted devices on iPad

About the 'Trust This Computer' alert on your iPhone, iPad or iPod touch – Apple Support (UK)

I assume there is some "handshake" problem after update (?) (whether on macOS or iPadOS, can't tell).

Hopefully it will help others (I will report this also on chat support to add this to their guidelines, before proposing to reinstall any of the devices).

So here we go again... when I got notification, that there is update 12.3.1 available for macOS, I lost ability to Screen Mirror (SideCar) to my iPad > the option wasn't there, even though iPad was recognized on macOS and I was able to share data. There was also update 15.4.1 on iPadOS so I updated both. After that, the issue persisted, so I tried my previous solution (reseting location & privacy on iPad), but it didn't work. I tried also connecting through WiFi and also Universal Control, which also did not work and though I was seeing the option to Screen Mirror to my iPad, I was getting "Device Timed Out" error.

What fixed the issue this time, was logging of and signing again to Apple ID on both devices. First trying SideCar through WiFi, then through USB and now it works again.

You (Apple) really should have a look at this issue, since now it seems to be affecting every update. Thanks.

I've been experience the same and I am getting to the conclusion that it is my bluetooth keyboard causing the issue.

My keyboard disconnects automatically if it is inactive for ten minutes, and every time it reconnects, the sidecar will lose connection soon.

As long as I don't use the keyboard, sidecar can run stably for hours. I'll turn the autodisconnect feature on my keyboard off for more testing.

It looks like Monterey 12.1 and/or iPad OS 15.2 fixed this. I am finally able to use sidecar wirelessly.

I updated to the latest iPadOS on 1/8/22 and that seems to have resolved the issue.

I have a 2019 16" MBP running Monterey and a 12.9" iPad Pro running iOS 15.1. I upgraded from Big Sur yesterday, and before then SideCar was functioning fine. After Monterey completed, SideCar would connect to the iPad but it would be a black screen.

I did uninstall my Cisco VPN client software and then rebooted, but then SideCar would work only sometimes, and for a few minutes before disconnecting due to bad network quality. Other times the screen would freeze with a static image and no longer update.

What I had forgotten is that the trust relationships between devices often get cleared out/need to be refreshed after OS upgrades, so I plugged in the iPad directly to my MBP with a USB-C cable, told the iPad to trust the computer, and it's been working for me for about five minutes or so at this point. Maybe it's working now?

[EDIT] If I try to start up SideCar with an Elektron Overbridge plugin running it goes back to the old behavior, and if it isn't, I can get that behavior dragging the window back and forth between the MBP and iPad. If I run the Overbridge plugin while SideCar is running, I see a rust-colored frame with black cut-outs. It is routing audio, from the device to the host, however.

hi,

i have the same issue on a Mac mini M1 and iPad Pro M1. For me the cause is Cisco Any Connect. each time use my VPN with Cisco the sidecar don't work with the cable usb c but only wifi. I prefer by cable, because is more stable that per wifi.

Monterey version : 12.0.1

IpadOS : 15.2

Cisco AnyConnect : 4.10.01075

For my case, apparently the issue has been resolved after rebooting iPad. It's been stable for a few days with wired Sidecar though. For those who have the issue, I may encourage you to reboot iPad and see if it helps.

I use the iPad (8'th Generation running iPadOS 15.2) with the Mac (mini (2018)) but mostly using the mirror mode from iPad to Mac. This mode works very well even over WiFi.

I've tested the SideCar feature with Monterey 12.1 and it seems to work well at least for short periods. I noticed that it can pause occasionally when the WiFi connection is not delivering sufficient bandwidth.

Have those folks experiencing problems tried using a lightning cable between the Mac and the iPad? If I recall correctly, I had tested this once by using a cable while disabling WiFi. Such a wired connection should have higher bandwidth as well as less latency.

- Pie Lover

So, I think I may have found a solution (at least for today)... which is to turn on the touchbar on the iPad display. Prior to this it crashed appx 10 times for me and now it's not crashing... Hope this helps someone.

FYI - I'm on a Macbook with an M1 Chip and have still been having the issue (until I turned on touchbar)

I have a support case open about a Sidecar issue. I'm running 12.1 on a 2021 MacBook Pro and a 7th gen iPad on 15.2.1. I've found that toggling a VPN on/off via System Preferences causes the computer to crash when Sidecar is active via lightning to USB cable— the iPad display becomes unresponsive, the System Preferences app freezes, and the computer has to be shut down by using a long hold on the power button. The issue is easily replicable. It happens every time. I've also experienced similar apparently random Sidecar crashes that others are reporting in this thread, but I reported the VPN issue since I can replicate it. I've tried disabling passcode on the iPad and turning on the touch bar as others have suggested. I can't report on whether these hacks solve the random Sidecar issues for me, but they do not fix the crash that happens when I toggle the VPN setting. As I mentioned, I'm tethering the iPad to the computer using a USB cable. I've tried various combinations of iPad wifi/bluetooth settings while tethered and it crashes for all. To my surprise, the crash does not occur when using Sidecar wirelessly. I can toggle the VPN setting while connected to the iPad via wifi/bluetooth (no USB cable) without freezing the computer.

It's worth trying, yes.

Rebooting the iPad Pro (4th gen) works for me most of the time, but not always. If it doesn't work it's mostly the connection failing or the connection is made but I only get a black screen on the iPad where an macOS desktop should be.

When rebooting fixes the problem it may last for a couple of days, but not permanently.

A buddy of mine says he found a fix for his sidecar/Monterey issues. I haven't seen it so I can't confirm. But, he's never been one to lie or exaggerate : Sidecar does not work if IPv6 is disabled. 

I'm on macOS 12.5.1 (MacBook Air M1), and on iPad Pro (M1) iPadOS 15.3.1 and there are several instances where the screen freezes (wireless). It is better when I have my thunderbolt cable connected to Mac, but it's just annoying that there are freezes when I use Sidecar wirelessly.

I'm experiencing improved connections as well.

Updated to iPad OS 15.2 a few days ago, while still on Monterey 12.0.1. Sidecar-support seems a lot more stable.