Sidecar not working on Big Sur and iPad OS

Someone mentioned before and worked for me: turn off your Macbook. logout iPad from iCloud totally; restart it, log in to iCloud again. Restart your Macbook. Check if they are in the same wifi, bluetooth and handoff on. Go to control center>display and it should show the iPad. Pick ir for mirroring/sidecar

This worked for me. Just signing out and back in did not.

Although logging out of iCloud worked for me, it’s a very poor solution. You then have to reset things such as re-enabling keychain on iCloud, responding to multiple devices telling you you have registered a new device, re-enabling find my iPhone, re-registering all your credit cards - which results in your providers re-sending physical letters with the bank’s T&Cs... Only do it if you have an hour or so to deal with the fall-out.

I'm sorry to hear that, as far as I remember that was the thing that worked for me.

Try one more thing: log out if your iCloud account on the iPad and then log back in. I think I did that simultaneously, but can't remember exactly.

I have the same issue but if you use cabling connection is working

I had to re-start the iPad after logging out and back in to iCloud. Then Sidecar finally worked wirelessly. Prior to this it only worked over USB. (MacBook Air M1, iPad Pro 2020).

What I did was to reset my whole MacBook and then reinstalled Mac OS Big Sur. And now it works👌🏻

Instead of logging out and back in to iCloud, I did the trick just by slightly changing the photo in the Mac's iCloud account and waiting for the same change to show up on the iPad.

Try to reset networks on the iPad first before reinstalling .

Similar issues here after installing Big Sur. Biggest issue is using the iPad 6th gen for sidecar as a wired connection to my iMac 2018 (i5 6 core). Weirdly get a cyan square middle of the iPad screen, which according to apple support when connected with me showed as a desktop space (not accessible locally though). Resetting iCloud setting provided temporary relief for a couple of days and this has now reverted back to giving the cyan square on the iPad when wired. It seems more tolerant of connecting via WiFi, which works as long as you have power, with fewer sporadic disconnections.

Combined with poorer boot and login performance so far, for me Big Sur has proven to be a big mistake to have installed.

Thank you for your reply.

I had the same issue as you and I found my iPad device by signing out and signing in, and then I encountered the "time out" issue. But unlikely, I did not find my device was listed twice in my iCloud, and I am still struggling with "time out" problem...

I'm pretty certain the option you're looking for is found in the following screenshot:

Alternatively, you can drag and drop the display option directly from within the "control center" in the menu bar.

To turn off/on sidecar from that point, you just click on your iPad from the "display" menu bar dropdown

I was able to finally fix it by toggling off "Keep Today View on Home Screen" by going to Settings > Home Screen & Dock and toggling it off on my iPad Pro

Sidecar paired wireless perfectly OK my 2019 MacBook Pro and my iPad Pro, running Catalina.

Now I'm on Big Sur and iPad OS 14.2, Sidecar NO WAY works.

Quite dissapointing...

I didn't know Catalina supported it. My Catalina Mac doesn't support it.

Interestingly, mine didn't work, either. It worked before.

I signed out of iCloud on the iPad and back in. The iPad shows up, but I cannot connect to it.

iPad 6th generation, 14.2, signed in with same Apple ID with 2 factor identification as mac mini 2018 running Big Sur 11.0.1, one foot away from the mini, same wifi network, bluetooth on on both, Handoff on on both, both devices show up in my account, and I get the same as the screenshot above.

It worked fine on Catalina.